Discovering Gerardo Parra's Potential

Having discovered the joys of SB Nation's Baseball-Reference account and of the Play Index feature's ability to sort through all of the records of baseball history (should one so desire) to find matches for almost any useful inquiry you might have, I've decided I may as well have some fun with the tool during the current lull I'm in at school between the last round of midterm exams and the onset of final exams.  In the midst of a recent comment thread about the prospects of the D-backs' hopes for 2012, a brief discussion came up on Gerardo Parra.  Parra certainly had a career year in 2011 than either of his previous two campaigns, but will 2011 prove to be something of a career year for Parra even when compared to what the future holds for the young left fielder?  Or, on the other hand, could Parra simply just be getting started, having completed what was just his age-24 season?  Follow after the jump to see how I try to take a glimpse into the young left fielder's future.

From a more traditional scouting perspective, the idea seems almost ludicrous.  Coming up through the minors, Parra was labelled as a tweener.  His line drive swing provided omens for good contact, but his swing didn't contain much loft, which left scouts wondering if he'd ever hit for enough power to regularly fill in a corner outfield spot.  On the other hand, while his arm is spectacular, his range and instincts in center field aren't quite up to par, so scouts similarly wondered if he would have the glove to stick as a regular in center field, where his bat would play better.  I think we've all seen plenty of Parra as a center fielder in the last three years to not want to see more of him there, but I'd say he's worked out rather nicely in a corner, albeit in an unorthodox manner.

He still doesn't hit with the traditional thump of a corner outfield slugger, but his Gold Glove award this year - a duly-earned one, I might add - at just 24 years old is an indicator of his phenomenal range for a corner player and his absolute rocket arm.  I'll redirect you to the Gerardo Parra Gold Glove Highlight Reel post that Jim graced us with after the awards were announced for further details... and simply because it's fun to watch, even still.

But this isn't a post to praise Parra for his well-documented exploits in the field.  Rather, this is a post to see if there's any real historical precedent for the kind of career that someone with Parra's track record through age-24 goes on to have.  Sadly, one slight limitation of the B-R Play Index tool is that it doesn't allow you to cap data ranges - you can set a constraint that a statistic has to be >=, =, or <=, but not any combination of the two without using two separate slots, and I'm going to need all four of them for separate statistics.  Thankfully, I possess a functioning human brain that is capable of sorting through the data and applying these constraints manually, so I'll be able to handily circumvent this little issue.

The statistics I'll be looking at, since B-R doesn't provide wOBA, are batting average, on-base percentage, slugging percentage, and Fielding WAR (which really ought to be titled Fielding RAR, but the idea is the same).  I'll first apply a series of decreasing ranges around Parra's career averages in those statistics, seeing which players provide particularly close comparisons for Parra and which provide less strong, but still worthwhile, comparisons.  We'll go through a case-by-case career profile to see if there's some merit behind the names that crop up, and to see how their careers progressed.

The first range will be within .15 of the three offensive categories, and within 8 runs of Rfield.  The second range will be within .20 of the three offensive categories and within 10 runs of Rfield.  The final range will be within .25 of the three offensive categories and within 12 runs of Rfield.  All three ranges will have a minimum of 1,000 plate appearances.  Parra's career averages in these categories are as follows: 1,377 PA, .282 BA, .331 OBP, .403 SLG, 23 Rfield.

In doing this, I came up with five names in the first range, an additional six names in the second range, and 13 more squeaking in in the third range.  Here's a link for all of the players to meet the lower bound thresholds for the first range.  Here's a link for all of the players to meet the lower bound thresholds for the second range.  Here's a link for all of the players to meet the lower bound thresholds for the third range.  And, finally, here is the data I was gathering with upper bounds considered and the leftover flotsam discarded, plus case-by-case analysis to see if the comparison has merit:

Range 1:

Warren Cromartie - The fifth overall pick in the 1973 draft, Cromartie made his big-league debut in1974 at the ripe young age of 20, but notched just 20 plate appearances that year for the Montreal Expos.  He would join the Expos to stay in 1976, and had a bit of a peak year at 24 in 1978, hitting .297/.337/.418, good for a wOBA of .335 and a wRC+ of 110.  He would only eclipse that wRC+ total two other times in his career, at age 27 in 1981, when he hit .304/.370/.419 with a .348 wOBA and 118 wRC+ while playing in just 99 games, and at age 37 in 1991, after a seven-year absence from the major leagues, when he hit .313/.381/.420 in 69 games for the Royals, good for a .354 wOBA and single-season career-best 119 wRC+.

While Cromartie's bat was simply average for his career, with a 102 wRC+ parts of ten seasons, he was stellar in the field, registering a total of 71 Rfield in his career according to B-R (FanGraphs' UZR data does not go that far back - they use TZ as well for Cromartie).  He placed 24th in MVP balloting in 1981, but was more of a solid player than a star due to his lack of power, with just three double-digit home run seasons.  Cromartie spent 2,165 innings in his career at first base, where he was worth 0 TZ and where his his excellent outfield glove, which was responsible for Cromartie's entire career TZ value in 6,649.2 career innings, was wasted.

Cromartie was not a star, but a solid player who contributed 18.9 career fWAR in just 1107 career big-league games, good for about 2.6 fWAR per 150-game season (even after being dragged down by his time at first base).  Parra following in Cromartie's footsteps likely wouldn't be a best-case scenario, but he'd still be an everyday-caliber left fielder through his remaining four years of team control.

Tony Fernandez - Tony Fernandez was a phenomenal infielder, playing 13,464.1 innings at shortstop in a big-league career that started at age 21 in 1983 and lasted until 2001, when Fernandez was 39 years old.  Fernandez also spent a combined 4,085.2 innings at second base and third base, but had a combined TZ of -11 between the two positions.  Where Fernandez starred was at short, where his career TZ mark of 43 is utterly fantastic, particularly for someone who posted a career batting line of .288/.347/.399, good for a .332 wOBA and 102 wRC+.  For a shortstop with a plus glove, that's utterly remarkable.  Fernandez had four seasons in which he recorded 5.0 or more fWAR, and six straight seasons, from 1985 to 1990, in which he recorded at least 4.0 fWAR.

Fernandez's breakout season came in the first of those seasons, when he posted a .289/.340/.390 line in 161 games for Toronto as their 23-year-old everyday shortstop, which added up to a .327 wOBA and 99 wRC+ for the Blue Jays.  He followed that up with a .310/.338/.428 campaign as a 24-year-old, good for a .340 wOBA and 108 wRC+, being selected for his first All-Star game, earning a Gold Glove, and placing 14th in MVP voting.  Fernandez's bat improved again the following year at 25, as he put up a .322/.379/.426 line and .357 wOBA (117 wRC+) in 146 games.  However, his bat would never reach those same heights until two BABIP-fueled years at the tail-end of his career, during his second stint with the Jays (thanks to an out-of-nowhere power spike).

Definitely a star.  However, there is a significant issue in the ~14-run positional value difference between being an everyday shortstop and an everyday left fielder, so this comparison isn't exactly fair.  Fernandez's career hitting numbers are certainly not out of Parra's reach, and Parra's wRC+ in 2011 (109) was eerily close to Fernandez's in his age-24 campaign (108).  Fernandez's career 84.9-run positional value will be more along the lines of -60 for Parra if they have similar-length careers, so that 15-win difference would significantly drag down the career 47.7 fWAR of Fernandez.  If Parra can keep hitting like Fernandez did and keep his left field defensive dramatically above average, though, he'll be a quality everyday player with perhaps an occasional All-Star season, but not a star.

Ryne Sandberg - A Hall of Famer makes the list here, as Ryne Sandberg's numbers through age 24 are shockingly-close to Parra's.  However, there are some things to consider.  First, there's a positional value adjustment that needs to be made here, as Sandberg spent his career at second base, generating an extra ~10 runs per year because of that value.  Second, Parra will never be the kind of base-stealer or baserunner that Sandberg was, with slightly below-average overall baserunning through his first three years, compared to seven runs above-average from Sandberg through age-24 and 32 runs above-average for his career.  However, given how hyped up Sandberg's base-stealing exploits have been over the ages, with his 344 successful steals in 451 career attempts, that's a surprisingly small run career run value from baserunning.

However, third, and most importantly, while Parra has had a steady first few years with a slight spike in 2011, Sandberg was just okay at ages 21-23 before erupting at age-24, hitting a berserk .314/.367/.520, good for a .397 wOBA and 146 wRC+, being named to the All-Star team, winning a Gold Glove, winning a Silver Slugger, and winning some thing called the NL MVP that you might have heard of.  Aggregating the numbers up to age-24 doesn't quite capture this, but it's certainly a massive difference between the early career of Sandberg and the early career of Parra.  Call it a wild hunch, but I'm not anticipating any 8.1 fWAR seasons from Gerardo Parra.

Sandberg was a star and a Hall of Famer, but not someone who really fits as a comp with Parra despite the similar through-age-24 numbers.  I wish I could tell you to dream on Parra being the next Ryno, but it's just not true.

Edgardo Alfonzo - Alfonzo got an early start on his career, playing 101 games for the Mets in 1995 as a 21-year-old.  He played 123 games the following season as a 22-year-old, and combined for just a .269/.303/.363 line those two years, with a 79 wRC+ in '95 and a 74 wRC+ in '96.  He broke out in 1997 with a .315/.391/.432 triple-slash and 124 wRC+ (in part due to a lofty BABIP), following it up with a less-stellar .278/.355/.427 line in 1998, good for a 112 wRC+.  Alfonso had a stretch of six years in which he recorded more than 5 fWAR four times, and was a solidly-productive player through his age-30 season before collapsing rather unexpectedly at age 31, playing just 30 games in the big leagues at age 32 before his MLB career ended.  Alfonso finished as high as eighth in MVP voting and was an All-Star once.

Alfonzo was a star at his peak, but his peak didn't last particularly long.  As a second baseman/third baseman, he generated positional values of about 2 runs per year, so Parra is dug into an eight-run hole from the start.  Additionally, Alfonzo saw his ISO jump from .118 in '97 as a 23-year-old to .149 in '98 as a 24-year-old, then up to .197 in '99 at age 25.  If Parra's career is going to follow that of Alfonzo's, he'll need to dramatically improve his power production in 2012.  When looking at Alfonzo's career path, it's hard to not at least think about the possibility that his power surge was generated with some help from steroids, given his sudden power spike and his quick demise in '05/'06.  However, Alfonzo wasn't much bigger than Parra is - Alfonzo is listed at 5'11", 210, while Parra is 5'11", 195 - so if Alfonzo's power boost was not artificially enhanced, there's a chance for a real surge from Parra in 2012.  If Parra can rake the way Alfonzo did, he'll be a stud left fielder, even if loses a bit of his defensive value in the process.  If the glove stays strong, he could be a force.  Still, one of the more improbable examples out there.

Jim Fregosi - Fregosi was a big-leaguer at age 19, an everyday player and MVP vote-getter by 21, an 8-fWAR player by 22, and had received MVP votes in four different seasons by 24.  He also played from 1961 to 1978, and was moved off of shortstop shortly after leaving the Angels as a 30-year-old due to injuries, long before he otherwise should have been moved off the position.  He probably would have been a Hall of Famer otherwise.  Fregosi's offensive numbers were dramatically superior to Parra's when considering the context of an era that was far more pitcher-friendly, so there's really not much of a comparison here.

Almost-Hall-of-Famer, a star, and someone who is not at all comparable to Parra despite the raw numbers.

Range 2: (bold indicates constraint in which comparison player was below Low Bound of Range 1; italics indicates constraint in which comparison player was above High Bound of Range 1)

Coco Crisp: Crisp broke into the big-leagues in 2002 at age 22, the same age as Parra in his debut season, but appeared in just 32 games that year compared to Parra's 120.  Nonetheless, Crisp enjoyed similar offensive production in '02 to what Parra did in '09, hitting .260/.314/.386 with Cleveland, good for a .310 wOBA and 88 wRC+ - compared to a .313 wOBA and 82 wRC+ from Parra's '09.  Crisp then struggled at the plate in his second exposure to the big leagues in '03, hitting just .266/.302/.353, a drop in wOBA to .285 and in wRC+ to 72, while playing in 99 games for the Indians, which again was strikingly similar to Parra's sophomore slump of .261/.308/.371, with a wOBA of .291 and wRC+ of 71.

Crisp broke out in 2004 at 24 years old, playing in 139 games with the Indians and hitting .297/.344/.446, good for a .337 and 104 wRC+, which again coincide with Parra's age-24 breakout line of .292/.357/.427 from 2011, a .340 wOBA and 109 wRC+.  From there, Crisp improved again in 2005, seeing his wRC+ jump up to 117 and recording a stellar UZR figure to notch a phenomenal 5.2 fWAR season, putting him at the top of the Boston Red Sox's wishlist and earning him him a trade to Boston in a six-player trade that saw then-top-prospect Andy Marte - one of the more notable prospect busts/flameouts in recent history - sent to Cleveland.  Crisp struggled in Boston for any of numerous reasons - a poor fit in the park, the big-time Boston atmosphere, injuries, you name it - and was unceremoniously dumped on the Royals in '09.  However, he has since joined the Oakland A's and remains a quality offensive player capable of playing a good center field... so long as he's healthy.

The resemblance here through age-24 is incredible.  The difference between Crisp's and Parra's Rfield is made up in large part by the similar discrepancy between their positional values, at least according to Baseball-Reference, while their bats are awfully similar both in lump stats and in how they trended from year-to-year.  Crisp is no star, but he has notched a total of 24.1 fWAR in 1043 career games, good for about 3.5 fWAR per 150 games.  However, Crisp posted some of his best UZR seasons after age-24, meaning that Parra will either have to continue improving upon his current defensive prowess or exceed Crisp's precedent at the plate in order to keep pace with Crisp given the positional discrepancy.  However, at least there's one case of historical precedent for it (hint: this one).  Definitely a comp to keep in mind.

Barry Larkin: In 1988, at age 24, Barry Larkin hit .296/.347/.429.  In 2011, at age 24, Gerardo Parra hit. 292/.357/.427.  In 1988, Barry Larkin posted a .357 wOBA and a 128 wRC+.  In 2011, Gerardo Parra posted a .340 wOBA and 109 wRC+.  Confusing, isn't it?  Well, before you cry that the whole system is flawed, know that Larkin also was 40-47 in stolen base attempts in that 1988 season and that the value of those stolen base attempts is factored into his wOBA and thus his wRC+, so there is some explanation to it all.  Indeed, Larkin's career 379-456 stolen base success rate is something that Parra will never be able to match, but that doesn't mean that Parra can't match, for instance, the career triple-slash of Larkin: .295/.371/.444 line in 9,057 career plate appearances.

After all, Parra tops Larkin in OPS in each of their respective three seasons in the big-leagues, and with Larkin listed at 6'0", 185, there isn't any reason to suspect that Parra won't be able to hit with as much authority as Larkin did.  Of course, Larkin, a shortstop, has the issue of positional value on Parra from the get-go, but Parra's current career TZ is just 5 less than Larkin's entire career TZ, and Parra's UZR agrees with the assessment that TZ has on his defensive abilities.  The combined efforts of Parra's defensive value and negative positional adjustment will probably be beaten by the combined positive positional adjustment and TZ of Larkin, but the one thing Larkin provides more than anything else is possible upside for what Parra might be able to do at the plate if all goes well.

Larkin is obviously a star, and a strong candidate to join the Hall of Fame, but Parra falls short in two main categories - defensive/positional value and baserunning value.  However, if Parra is able to keep up with Larkin at the plate and hit for something vaguely resembling the .295/.371/.444 career line that Larkin posted, we'll have ourselves a strong everyday corner outfielder who will make more than one All-Star appearance.  That, however, looks to be a best-case scenario for Parra.

George Wright: It's hard to find much information on what happened to Wright, whose career went into a tailspin after a strong 1983 season, largely because there's a different player by the same name who happens to be in the Hall of Fame, thus rendering Google searches rather useless.  The George Wright that came up in this study is not the 1800's shortstop for the "Boston Red Stockings," but is in fact the young outfielder who played just five MLB seasons from 1982-1986, garnering MVP votes in '83, his age-24 season, and then posting a combined -5.4 fWAR in just three seasons, earning his departure from MLB.  I honestly have no idea what caused Wright's spectacular flameout, but I'm fairly confident that Parra is unlikely to follow in Wright's footsteps simply because the team would find other alternatives before he stooped quite that low.  His brief Wikipedia page mentions something about injuries, but goes into little detail.  Quite an intriguing case.

A complete bust, and it's pretty hard to see Parra following suit.  Despite Wright's MVP votes, Parra's age-24 season was actually quite a bit better than Wright's mostly because of Wright's reluctance to draw a walk, which was a strong suit of Parra's in 2011.

Melky Cabrera: Cabrera, who reached the major leagues at 20 years old and played 130 games as a 21-year-old with the Yankees, notched 2,148 plate appearances through his age-24 season.  He showed dramatically inferior power to what Parra has put up thus far in his career, as his slugging percentage fell below the lower bound of the first range of comparisons for Parra.  Additionally, while Parra's bat broke above league-average in 2011 with a 109 wRC+, Cabrera maxed out with a 98 wRC+ in his age-21 season during his Yankees tenure until finally breaking out with the bat in 2011 - though whether or not it was a sustainable breakout is another question, and one that the Giants are hoping they know they answer to.  Still, Cabrera's offensive production through age-24 isn't a great comparison for Parra - in spite of an age-23 down year like Parra's - as Cabrera's age-21 season was better than any of the following three seasons, whereas Parra's age-21 season was spent in the minor leagues.

Additionally, there is a serious divide between the perceptions of Cabrera's defensive value provided by TZ and UZR.  If TZ is to be believed, Cabrera's fielding runs above average stood at +14, with a -4 positional adjustment for a combined +10.  If UZR is to be believed, though, Cabrera's fielding runs above average sink all the way to -4.1, with a positional adjustment of -3.7, for a combined -7.8!  Oddly enough, both systems more or less agree that Cabrera has been an awful defender since, with a TZ of -23 and a UZR of -19.4, while manning all three outfield spots for Atlanta in 2010 and primarily playing center field for the Royals in 2011.

With serious questions as to Cabrera's true defensive value through age 24 and an offensive profile that doesn't match up with Parra's particularly well, Cabrera seems like a lackluster comp for the D-backs outfielder.  Which I'm quite happy with, frankly.

Jhonny Peralta: Peralta provides another interesting, though perhaps not particularly informative, career example to compare with Parra.  Peralta received only occasional playing time for the Indians in his age-21 and age-22 seasons, posting a combined .228/.297/.322 line in 298 plate appearances, good for a combined total of exactly replacement-level production in those years per FanGraphs.  Then, out of nowhere, 2005, Peralta's age-23 season, happened.  Peralta spent the entire season as the Indians' everyday shortstop and posted a .292/.366/.520 line, clobbering 24 home runs, posting an ISO of .228, sporting a .346 BABIP, and ultimately finishing with a .376 wOBA and 134 wRC+.  UZR didn't think too kindly of his glove at -6.1 runs, but TZ gave him a +9 defensive rating, which essentially means that Peralta either played like an All-Star or a superstar, depending on which defensive system you believe.

A funny thing happened, though.  Of all of the offensive statistics from his '05 season listed in that previous paragraph, he has matched exactly one of them in one other season of his career, by posting a .299 batting average with the Tigers just this year.  Yep, that '05 campaign still stands as his career-high season in terms of OBP, SLG, ISO, BABIP, and HR.  Peralta's career since has been exceptionally inconsistent, including a move to third base in 2009 and a move back to shortstop in 2011, following a 134 wRC+ season with an 84 wRC+ season, later following an 89 wRC+ season with a 120 wRC+ season, and accumulating -23 UZR (but just -5 TZ, go figure) in '06 and '07 - his age-24 and age-25 seasons - at shortstop but then posting a 9.9 UZR in '11 - his age-29 season - once again at shortstop.

Peralta also doesn't match Parra particularly well in the trends of their offensive production.  For one, Peralta wasn't nearly the hitter for average that Parra is during his youth.  Second, Peralta saw a massive regression in his offensive skills at age 24, while that was the age at which Parra broke out at the plate.  However, Peralta does provide an instance where someone's offensive output through age-24 didn't dramatically improve - or decline, for that matter - throughout the rest of their career.  After hitting .264/.334/.423 through age-24, Peralta's current career average line is .268/.330/.427, for a 100 wRC+.  Now that's consistency.  Needless to say, it wouldn't bode particularly well for Parra if he failed to improve upon his current career-average line of .282/.330/.403, which is merely a wRC+ of 88.

Bobby Tolan: Tolan was on his way to a phenomenal career through age 24, with back-to-back seasons of >.820 OPS marks in 1969 and 1970 at ages 23 and 24 while primarily manning center field for the Reds.  Then, Tolan ruptured his Achilles in the off-season and missed all of 1971, had a solid year in 1972, but saw his career quickly collapse thereafter, last playing in over 100 games in a single season in 1976, at age 30.  While Tolan's raw numbers might look vaguely similar to Parra's, those two career years saw him post wRC+ figures of 125 and 138, figures that were as much a product of a different era as they were of the gap between his performance and Parra's.

In the end, both the 40-year gap and the career-derailing injury make this a flawed comparison, much as the raw data might match.

Range 3: (bold indicates constraint in which comparison player was below Low Bound of Range 2; italics indicates constraint in which comparison player was above High Bound of Range 2)

Aaron Hill: First, to get the obvious detail out of the way - Hill is a second baseman, and gets a positive positional adjustment that Parra does not get.  However, Hill's career UZR/150 of 4.2 at second base plus a positional adjustment of approximately two runs is only about a run higher than the 11.1 UZR/150 Parra has in left field (it's 14.0 in RF) minus the six run positional adjustment (though it's worth noting that Hill's career TZ/150 dwarfs his UZR/150).  So, if Parra is able to keep up his defensive excellence in the corner outfield, he could have a very similar defensive profile to Hill's (per UZR).  Additionally, if Parra's takes a step forward at the plate like Hill's did from his age-24 season to his age-25 season, 2012 could be a great season for Parra, as Hill upped his wRC+ from 90 at age 24 in '06 to 106 at age 25 in '07.

What Hill also provides us is a good case study for a hitter with a similar set of offensive strengths as Parra has - spraying line drives to all fields with the occasional ability to turn on a ball and pull it into the bleachers.  That kind of approach helped Hill spray line drives to all fields in his first three years in the big leagues, and even in his home run happy '09 season, Hill had a LD% of 19.6%.  However, when Hill went awry, it seemed to be because he was too preoccupied with trying to get under the ball and try to drive it out of the park rather than trying to stick to his strength of shooting frozen ropes into the outfield.  Hill's truly awful stretches in the big-leagues - '08, '10, and '11 with Toronto - have been marked by the three lowest LD% figures of his career.  But when Hill is shooting line drives around the park, he's an above-average hitter, which makes for a darn good player with that defensive value.

Hill has had a bit of an up-and-down career, but with spurts of greatness when his approach is right.  With Hill standing at 5'11", 205 to Parra's 5'11", 195, it's not at all unreasonable to believe that Parra's power can progress like Hill's has, but it will be important for Parra to not become so fly-ball-crazed like Hill did at times in Toronto.  Hill's '09 HR/FB rate was a fluke that probably did him more harm than good in the long-run (i.e. he tried to hit more fly balls as his HR/FB regressed in an attempt to keep hitting HRs at that pace), but he showed in '07 that 15-20 home runs is very possible while maintaining a balanced, line-drive-friendly approach.

Although Parra's increased ability to yank a ball down the right field line in 2011 is good for him as a hitter when it comes to punishing mistakes and making pitchers respect your ability to handle stuff on the inner half of the plate, his biggest strength will always be spraying line drives to all field, not hitting home runs.  What made Parra's 2011 campaign so successful was his continuing improvement in LD%, with a 22.4% figure that has trended up in each of the last two years.  If he keeps with that trend, he'll be a fine hitter and a consistent ~3.5-win player, as Hill was in '07.

Rafael Furcal: If Gerardo Parra were right-handed, there's a solid argument to be made that he would essentially be Rafael Furcal.  Parra might not be quite agile enough for shortstop, but frankly, Furcal hasn't always been the most fleet-footed player there in his career, either.  Rather, Furcal has made a career out of his grade-80 arm at the position, high batting averages, willingness to talk a walk, and 10-15 home run power.  TZ has loved Furcal's defense, giving Furcal a career 45 runs above-average ranking at short, but UZR hasn't thought so highly of him, ranking Furcal at -9.1 runs in his career.

If you combine Furcal's career positional adjustment of 63.8 with that UZR and put the resulting figure in terms of a 150-game season, you wind up with a total defensive value of 5.5 runs per 150 games, which is, scarily enough, exactly the same as Parra's UZR/150 in left field - 11.1 - minus the positional adjustment he had for the 2011 season, -5.6.  A full season in left would probably require a more significant positional adjustment, but that would make for a difference of a run or two.  The question, therefore, becomes whether or not Parra's bat will be able to hold up to what Furcal has done over his career.

Parra has an advantage over Furcal in terms of pure slugging percentage early in their respective careers, but part of that is undoubtedly the product of playing at Chase Field.  However, Parra's peak wRC+ of 109 is the same as Furcal's best through-24 wRC+, which Furcal registered at age-22 with the Braves.  Furcal tailed off significantly after that season with a pair of mid-80's wRC+ seasons before breaking out again at age 25, largely due to a spike in ISO that he sustained for a good portion of his career.  Furcal had four straight seasons of league-average or better offensive production from age 25 to age 28 before a down year in 2007 with L.A. and the eventual onset of injuries.  Nonetheless, Furcal has been a career 103 wRC+ hitter and managed 36.1 career fWAR in 1,484 games, or roughly 3.6 fWAR per 150 games.

If 5'8", 187-pound Rafael Furcal can have a significant ISO boost at age-25, I see no reason why Gerardo Parra cannot.  Therefore, if Parra is able to sustain his career levels of defensive wizardry in left field, he could truly blossom into the same type of player that Furcal has been throughout his career - worth about 3.5 wins on average, and occasionally reaching into star-caliber production levels in offensive peak years.

Leo Cardenas: I'll give you the good news first - Parra's bat is vastly superior to Cardenas'.  Cardenas is the only player listed in this range whose OBP and SLG both were too low for the second range, so fears that Parra's bat is destined for the career.257/.311/.367 line and 85 wRC+ that Cardenas put up over his 16 big-league seasons can be put to rest.  Now, for the bad news - Cardenas' glove is vastly superior to Parra's.  Manning shortstop for all but 440.2 of his 16,446 big-league innings in the field, Cardenas put up a career 30 TZ and a 110.6 positional adjustment, for a +140.6 glove in his career and +10.9 glove per 150 games.  Parra would have to post UZR/TZ figures around +17 for his career to make up for the positional adjustment that playing in left field will bring.

Just not much of a comparison here.  Cardenas only cracked the list in the first place because of a .359-BABIP-fueled career-high 120 wRC+ at age 22, and he was above-league-average offensively in just three other seasons of his career.  Meanwhile, it will take an amazing (likely luck-based) fluctuation in Parra's UZR and TZ for him to ever approach a +11 season with the glove that Cardenas posted in his career-average season.

Bill Buckner: Yes, that Bill Buckner.  Buckner played in the big-leagues in four different decades, debuting at age 19 with one plate appearance for the Dodgers in 1969 and retiring after playing 22 games for the Red Sox in 1990 at age 40.  Listed at a mere 6'0" and 185 pounds, Buckner nonetheless spent most of his career at first base, with just 658 games (out of 2517 in his career) in the corner outfield.  This becomes all the more peculiar when you consider that Buckner's career TZ in the outfield was 26, compared to a depressing -13 in 1,555 games at first, where there is a much harsher positional adjustment.  For a first baseman, Buckner was surprisingly inept offensively, posting above-league-average wRC+ figures in just eight of his 22 big-league seasons, although his breakout 119 wRC+ at age 24 aligns nicely with Parra's 2011 breakout campaign.

With just 24.6 career fWAR across those 22 seasons, it's rather shocking that Buckner finished in the top-10 in MVP voting twice, although he did post 4+ fWAR seasons on two occasions.  Even more interesting, though, is that Buckner's top-10 MVP finishes came in neither of those 4+ fWAR seasons - rather, Buckner put up fWAR totals of 1.9 and 1.8 in those top-10 seasons, which were in 1980 and 1981.  Now, while Buckner didn't have the kind of power or sustained offensive peak one would hope to see from a first baseman, his bat would have been great for a corner outfielder in his prime, and his career .289/.321/.408 line is heavily dragged down by receiving a ton of plate appearances past his prime, which ended with the second of Buckner's two top-10 MVP finishes.  From age-33 to age-40, Buckner hit just .274/.308/.399, yet received 3,621 plate appearances.

If you look at just Buckner's prime, from ages 26 to 32 (1976-1982), you find respective year-by-year wRC+ totals of 108, 85, 101, 93, 113, 124, and 112.  Those are extremely underwhelming numbers for a first baseman, which is what Buckner was for all but one of those seasons.  However, the one year that Buckner did play in left field, '76, he posted a TZ of 16 and wRC+ of 108, leading to his highest single-season fWAR total of 4.3.

Buckner is a generally mediocre comparison for Parra given the fact that Buckner was largely a first baseman, but if you look past the defensive value, substituting Parra's UZR/150 of ~11 in left field with a left field positional adjustment, and instead to the pure trends of offensive production, Buckner provides an awfully similar range of potential peak values for Parra, right in the 3.5-win range.

Andy Carey: There are lots of reasons to be skeptical about a Carey/Parra comparison.  For starters, Carey played from 1952 to 1962, so the offensive climate was dramatically different.  More important than that, though, is that Carey's bat got steadily worse from age-21 to age-24, with a 152 wRC+ (though in just in 91 PA's) in 1953, a 123 wRC+ in 1954, an 87 wRC+ in 1955, and a 74 wRC+ in 1956 (> 470 PA in '54, '55, and '56).  Carey's wRC+ would eclipse 100 just one other time in his career.  Also, Carey played third base, although the TZ plus positional value of about 6 runs per 150 games does mirror Parra's career values thus far in left.

Much as I could try to average things out and make some sort of projection based on Carey's career, I find it hard to try to compare someone whose wRC+ was 109 in his age-24 season with someone whose wRC+ was 74 in his age-24 season, even if the aggregate numbers are vaguely comparable.

Terry Puhl: Puhl spent the '70s and '80's as a prominent member of the Houston Astros' outfield, spending most of his time in the corners.  Puhl's age-24 1981 season was underwhelming when compared to Parra's in terms of raw unadjusted numbers, as Puhl hit just .251/.315/.354 in 96 games, but that was still good for a 103 wRC+.  Additionally, that was the lowest single-season wRC+ total of Puhl's career through age 24, as he already had 2,192 plate appearances worth of .288/.355/.388 hitting across the four seasons prior to that 1981 season, posting respective wRC+ figures of 130 in '77, 109 in '78, 106 in '79, and 128 in '80.  So Puhl's bat was clearly superior to Parra's in the early parts of their careers.  Combined with a glove that posted a combined TZ plus positional adjustment per 150 games of about 4.4 through his age-24 season, Puhl was a force early in his career that Parra can't compare to.

Rennie Stennett: Rennie Stennett was one of the better second basemen in the game early in his career, with wRC+ totals between 93 and 98 in three of his first four seasons of 100+ games played, between ages 21 and 24.  His bat was clearly better in his early years than Parra's has been, although with less of an upward trend than Parra has seen (particularly at age 24), instead showing solid consistency.  After that age-24 campaign, Stennett had a decent 1976 season that was dragged down due to low BABIP and was on his way to a great 1977 season, with a 114 wRC+ in 116 games, before a broken leg ended his '77 season.  Following the broken leg, Stennett would never hit with authority again, never eclipsing a 61 wRC+ in the following four seasons.

Whether because of the broken leg or not, Stennett's bat absolutely imploded after his age-26 season.  He somehow received a five-year, $3MM contract after a second-straight awful year in 1979, but played just two seasons of it with the Giants before being cut and never resurfacing in the big-leagues.  Even if the early-career batting trends for Stennett don't resemble Parra's, Stennett provides a cautionary tale of how horribly wrong the development of a young stud can go.

David Green: Green was pretty bad.  No other way to say it, really.  He had one solid year in 1983 as a 23-year-old, hitting ..284/.325/.422, good for a 108 wRC+, but then regressed heavily in his age-24 season, hitting just .268/.297/.416.  Green, who spent about half of his time at first base and half of his time in the outfield, struggled again as a 25-year-old, hitting .248/.301/.347, good for a 80 wRC+ and a ticket out of the major leagues.  He resurfaced briefly in 1987, but for just 14 more games before his big-league career ended.

Green simply didn't have the on-base skills Parra showed in 2011, and trended steadily downward from his age-23 season until the end of his career, whereas Parra significantly improved from '10 to '11.  Since Green spent so much time at first, his bat simply didn't cut it after his solid '83 campaign.  Green a) never was as good at the plate as Parra was in 2011, and b) wasn't as good with the glove in the outfield as Parra has shown himself to be.

Jim Lefebvre: Lefebvre's career began in the 60's, back when a .274/.333/.460 line and .347 wOBA in your age-24 season was worth a 127 wRC+.  In 2011, Mark Reynolds had a .348 wOBA and 116 wRC+, while Jeff Francoeur had a .346 wOBA and 117 wRC+ (park factors explain the oddity there, of course).  Sadly, after putting up a 107 wRC+ at age 23 - winning the Rookie of the Year award that year - and that career year at age-24, Lefebvre's wRC+ never rose above 102 in any single season for the rest of his career.  Lefebvre's career was over by his 31st birthday.

While Lefebvre does offer another instance where a player's bat collapses steadily after his early-20's, it's worth noting that Lefebvre, like most of the other players in this post who experienced similar trends in offensive production, played in a much different era.  Medical science has made enormous progression since, and the wear-and-tear on bodies over multiple long, 150-game seasons has been diminished as a result.  It's no coincidence that guys like Lefebvre, Green, Stennett, Carey, and Tolan all collapsed so early.

Robin Ventura: Another phenomenal overall player, Ventura's career 112 wRC+, 161 TZ, and 61.2 fWAR are phenomenal marks for the former star third baseman.  However, it needs to be noted that even though Ventura was within this range of comparables, Ventura was a superior player in every way to Gerardo Parra in his age-23 and age-24 seasons (1991 and 1992).  In those two years combined, Ventura hit .283/.371/.437, with a 21 TZ and 12.7 fWAR.  Parra has managed to hit for about as much average as Ventura did in his early years, but Ventura dramatically bests Parra in terms of walk rate, power, and overall defensive value when Ventura's positive third base adjustment is considered.

An absolutely elite player, and one that Parra simply cannot compare to.

Jose Reyes: For several very obvious reasons, Gerardo Parra should never be compared to Jose Reyes.  Parra plays left field very well, but Jose Reyes plays shortstop pretty well, and playing shortstop pretty well is far more valuable than playing left field very well.  Additionally, Gerardo Parra is rather unlikely to amass 370 stolen bases in his career, and even more unlikely to do so while being caught stealing just 92 times.  Parra might manage to copy Reyes' career 112 wRC+ - though that would be a best-case-scenario - but even if he does so, it's a mortal lock that Parra doesn't replicate the kind of 6-win seasons that Reyes is capable of having if he's healthy.

So outside of a possible projection of pure hitting ability (and admittedly one that meshes well enough with our previous examples in the ~110 wRC+ range), there's really very little here as far as comparison goes.

Adam Jones: Jones and Parra are a very different hitters, and very different all-around athletes.  Jones is far more physically imposing, with a 6'3", 220-pound frame that offers far more power projection than Parra's build.  This goes a long way into explaining the .153 ISO that Jones put up through his age-24 season between Seattle and Baltimore, compared to the .120 ISO Parra has through his age-24 season at Chase Field.  Even if we wanted to try to make a comparison here, though, it'd be pretty difficult considering that Jones has only just completed his age-25 season...

If you're looking for a positive spin, though, it was the best season of Jones' career thus far.  Hooray for small positives!

Sixto Lezcano: Lezcano's first breakout campaign came in 1977 as a 23-year-old, as the right fielder hit for a .273/.358/.503 line in 109 games for Milwaukee after three mostly mediocre seasons in the big leagues.  Lezcano's power tailed off significantly the following season, but his on-base skills improved again, hitting .292/.377/.459 with Milwaukee again, this time in 132 games as a 24-year-old.  Given the vastly superior overall numbers and the different offensive climates of the time, Lezcano's triple-slash lines resulted in wRC+ figures of 134 in '77 and 135 in '78, cementing himself as one of the more deadly power hitters of the era.  How Lezcano did it with a frame that was listed at 5'10", 165 lbs. is beyond me, but he took his power to another level altogether at age-25, hitting a staggering .321/.414/.573 in 138 games as a 25-year-old in 1979, placing 15th in MVP voting and earning a Gold Glove.  However, Lezcano's career went mostly downhill from there, and the slugger had played his final big-league game by his 32nd birthday.

Lezcano was definitely a star, but Parra simply can't compare with Lezcano's staggeringly-good age-23 and age-24 offensive numbers, particularly when it comes to power.  If nothing else, though, Lezcano provides a comparison for someone who took his already-impressive offensive game to entirely new levels in his age-25 season, despite a frame that wouldn't typically be considered power-conducive.

Now, what to make of all of these comparisons?  Well, first, I think it's practical to put aside cases where a player's career was derailed by injuries and rapid attrition in what is now considered a player's prime years, the 27-29 range - which is more a separation between the pre-80's era and the post-80's era more than anything.  21st century medical practices have advanced so much that it is extremely unlikely that Parra collapses in his physical prime due to injury.  It certainly isn't an impossibility, but its likelihood seems small enough to me that, for the purposes of analyzing this data, it is negligible enough.

The best-case-scenario comparison for Parra is probably that his glove holds at its current UZR/150 standards and his bat resembles that of Barry Larkin, from the second range of players.  Parra's bat will have to progress in a spectacular fashion, so the odds are incredibly slim, but, well, that's why it's a best-case scenario.  Larkin's career of phenomenal base-stealing is a virtual impossibility for Parra, but if Parra's bat can progress the way Larkin's did without his glove dropping too far off, Parra could be a consistent four-plus win player throughout his prime, and perhaps see his share of All-Star appearances.

Of course, there also is a worst-case-scenario, and it bears mentioning.  If Parra's 2011 improvements prove hollow and his UZR takes a dive in 2012, there are examples to show how awry Parra's career could turn.  Even excluding cases where injury derailed promising careers, such as with George Wright, there are examples where the player simply didn't see his offensive production jump significantly after his 24th birthday, such as Melky Cabrera and Jhonny Peralta.  Perhaps Parra's drop would be minimal and he could maintain, say, a two-win level of performance, but it would be an underwhelming result considering the larger number of cases that suggest the promise for something more.  And if 2011 was a complete mirage, even that would be no guarantee.

However, the most comfortable range of comparisons in my mind are those in the 3-3.5 win range.  Comparisons like Warren Cromartie, Coco Crisp, Aaron Hill, Rafael Furcal, and even Bill Buckner (to a lesser extent) provide optimism that Parra could settle in as this sort of well-above-average everyday-caliber player in left field, providing a rare mix of above-average offense and superb defensive value.  The improvements Parra made at the plate in 2011 have to be legitimate and Parra needs his glove to remain stellar for this to happen (it will help to get him out of center field, where he posted a -2.1 UZR in just 10 innings in 2011), but his youth greatly increases the confidence I have in his ability to do this.

What the analysis of these comparable players showed me, more than anything, is that the 2011 campaign of Gerardo Parra was likely not a fluke (although I would be interested in seeing if anybody else gets something different out of this all).  Nothing is a certainty in baseball, but Parra's upward trend in production (particularly in his line drive rate) at his young age, combined with his overall body of work through his age-24 season, give him the look of a player who, in the modern era of baseball, has often turned into an above-average 3-win type of everyday bat.  With how much that comparable analysis agrees with the surge in production we saw from our left fielder in 2011, that seems to be the most likely outcome for Parra's career.