The Incredible Development of Gerardo Parra

In the second game of Arizona's three-game set against the Dodgers, Gerardo Parra took a first pitch at his face from left-hander Hong-Chih Kuo while squaring up to try to bunt for a base hit.  After working the count to 3-1 Parra obliterated an offering from Kuo into the right-center field bleachers, his second home run off of Kuo this year in as many plate appearances.  Aside from being kind of a badass moment (and one that Mark Grace thoroughly enjoyed), for lack of a better term, it was also remarkable due to the fact that Kuo has held lefties to a line of .208/.284/.323 over his entire career with just seven home runs, including Parra's pair of bombs in 2011.  Parra had faced Kuo just twice in his career prior to 2011, striking out both times.  The very next day, against perhaps the best left-hander in the National League, Clayton Kershaw, Parra crushed a double in his first (and, for all intents and purposes, only) plate appearance against Kershaw.

Yes, that is one of the sketchiest small sample size comparisons ever concocted, but for a guy who had three home runs in his entire 2010 season, who expected a pair of home runs in 2011 off of one of the best left-handed relievers in the game?  If you've watched a week's worth of D-backs baseball this year, you know that Parra is a dramatically improved player.  Naturally, this begs the question: how has he improved, is it sustainable, and could there be more to come?  Follow me after the break to take a look.

First, let's begin by starting some of the obvious points of improvement before later diving down behind the surface and seeing how legitimate the improvement really is.  I think the best way to truly appreciate the dramatic improvements in Parra's play is by putting all the numbers side-by-side and letting them speak for themselves:

Note: 2010 full-season stats, 2011 stats accurate through 9/13:

	GP:	PA:	BA:	OBP:	SLG:	wOBA:	wRC+:
2010:	133	393	.261	.308	.371	.291	71
2011:	128	442	.299	.360	.443	.347	113

	BB%:	K%:	ISO:	BABIP:	UZR:	SB:CS:	fWAR:	bWAR:
2010:	5.9%	19.3%	.110	.322	13.8	1:0	1.1	0.9
2011:	8.6%	17.4%	.144	.352	15.0	12:1	3.5	2.6

By the numbers, Parra has seemingly done everything better in 2011 than he did in 2010, and nobody will debate that point.  At the plate, he's improved his ability to hit for contact, draw walks, and hit for power - all three of the primary hitting skills.  The contact rate is partially because of a spike in BABIP, but Parra has also cut his strikeout rate by nearly two percentage points, so there seems to be legitimate improvement there.  We'll get into the walk rate much more in-depth later on, but for now it's sufficient to say that a nearly three percent spike in walk rate has turned Parra from a hacktastic low-OBP out-machine into the hitter with the 43rd-best OBP in all of baseball among players with at least 400 plate appearances.  The slugging percentage spike of over 30 points is also an enormous leap, and at just 24 years old, there's actually reason to believe that there could be more power left in Parra as he enters his prime seasons.

His defense has been remarkable, and with nearly a two-year sample of UZR suggesting he's worth about a win and a half above average per year in left field.  It's rare to find someone who is legitimately that much more valuable above average at a position - often, one-year wonders (like Franklin Gutierrez's 30+ UZR season) of UZR quickly regress back to just a few runs above-average the following season, as sudden spurts are often the product of small sample sizes, even over the course of an entire year.  If you questioned Parra's 13.8 UZR total from 2010, you were right in doing so, but in 2011 he has managed to prove that that loft total was no fluke, as both the numbers and Parra's routine spectacular plays agree that he has become an absolute weapon in left field.

However, I want to do a bit more with this post than simply state which production-based rate stats of Parra's have gone up this year.  I want to dive into those rates and see whether there are real signs of progress to back them up in the more complex, underlying peripherals.  For example, what should we make of Parra's BABIP spike in 2011?  One of the reasons Parra regressed at the plate from 2009 to 2010 was because his rookie-year BABIP of .346 dipped down to .322 in 2010 - still a significantly above-average total for a big-league hitter, but enough of a drop to cause Parra's batting average to suffer.  With few peripheral skills to support his batting average at the time, Parra's value suffered immensely.

However, take a look at Parra's batted ball distribution by year:

	LD%:	GB%:	FB%:	HR/FB%:	BUH%:
2009:	18.3%	52.8%	28.8%	4.7%	20.0%
2010:	20.3%	51.0%	28.7%	3.7%	33.3%
2011:	22.9%	47.9%	29.2%	8.7%	45.5%

The trends are pretty obvious.  Parra has steadily generated more consistent loft in his swing as his career has progressed, allowing him to significantly decrease the number of ground balls he slaps on the ground and replace them mostly with line drives, although he is also hitting a few more fly balls this year.  With an increasing line drive rate, it shouldn't be too surprising that he has seen his BABIP in 2011 exceed his career BABIP of .341.  Yes, that career BABIP is enormous compared to the average hitter, but there are reasons to believe it.  The biggest reason to believe it is simply that he's sustained that high figure for over 1,300 plate appearances - we've passed the small sample size threshold by this point.

Additionally, ground ball hitters will typically have higher BABIPs than fly ball hitters, so we ought to expect Parra's rate to be at least slightly higher than a typical big-leaguer's BABIP even without the established history of data.  With his line drive rate continuing to increase over the last few years, there's even more reason to expect that the inflation can be sustained.  If that still isn't enough evidence for you, the slight increase in fly balls hasn't affected his BABIP this year in part because they simply haven't been staying in play.  Parra's HR/FB has spiked significantly in 2011 - in my mind, a product of him working with hitting coach Don Baylor on pulling the ball, which he rarely did before this year - and given that he's all of 24 years old, he ought to be able to keep a HR/FB somewhere in the 8% range through the next few years and into his prime.

I'm not saying that Parra will undoubtedly see his BABIP remain above .350 for the rest of his career - this isn't impossible, but it's certainly improbable for any big-league player.  However, I do think it's fair to expect him to remain at least mildly close to his career BABIP, perhaps winding up somewhere in the .330 range long-term.  If he is able to continue developing his power, patience, and contact skills throughout his early-to-mid-20's and avoid major regression of his skills, that will make for a fantastic hitter.

However, there's also a question as to whether or not Parra's plate discipline improvement is legitimate, or if it's the product of him hitting in front of the pitcher for much of the year.  First, let's take a look at his walk rates by spot in the lineup in 2011:

	PA:	Walks:	IBB:	BB%:	(BB-IBB)%:
Hitting 8th	277	24	13	8.66%	3.97%
Hitting Elsewhere	165	14	1	8.48%	7.88%

Looking just at the "Hitting 8th" row, you might think that all your greatest fears about Parra's plate discipline have been confirmed.  His straight walk rate is significantly elevated, but much of that "progress" appears to be due to over half of his walks in the eighth slot in the lineup coming in the form of intentional free passes.  However, by also taking a look at what he's done elsewhere in the lineup, we see that Parra has indeed seen his unintentional walk rate jump nearly four percent above his unintentional walk rate in the 8-hole.  So, what gives?

This may seem a bit counter-intuitive to traditional baseball logic, but isn't it possible that the eighth spot in the lineup, despite inflating overall walk rate, could suppress unintentional walk rate?  After all, consider the circumstances in which a pitcher would want to intentionally walk the 8-hitter.  The scenario that instantly comes to mind, at least for me, is two outs, first base open, and possibly runners in scoring position.  Outside of the eight-spot, though, those are exactly the types of situations where a pitcher might be more willing to flirt outside of the strike zone and risk an unintentional walk on the off-chance that the hitter swings and junk and bails the pitcher out of that rough situation.  In other situations - i.e. fewer than two outs just in front of the pitcher with first base not open - not throwing strikes and walking the eight-hitter unintentionally is a major mistake, because it guarantees that the pitcher will be able to bunt over the runners and won't kill the rally.

So, in other words, hitting in the eighth spot eliminates many of the situations in which a hitter could have the highest chance to draw an unintentional walk, because the hitter is instead unintentionally walked at those times.  To provide some empiric evidence of this trend rather than relying on suppositions, let's take a look at some other hitters who have spent a lot of time in the 8-hole throughout their careers, and calculate the difference in their unintentional walk rates while hitting eighth and hitting elsewhere in the lineup.

Let's begin with one familiar to Arizona fans, Chris Snyder:

	PA:	Walks:	IBB:	BB%:	(BB-IBB)%:
Hitting 8th	1229	155	29	12.61%	10.25%
Hitting Elsewhere	948	119	3	12.55%	12.24%

What makes Snyder a particularly good example is that even when he was at his best offensively in his career - 2008, his only full season with an OPS+ above 100 - he still spent a lot of time hitting 8th.  Therefore, we don't face possible bias with Snyder hitting eighth early in his career when he was developing as a hitter and didn't draw as many walks, then moving up in the lineup later on when his patience was more developed.  As the numbers clearly show, Snyder drew slightly more walks in the eight spot in the lineup, but dramatically fewer unintentional walks while hitting eighth.

This is far from a significant enough sample to define a correlation - for example, Chris Ianetta has a higher career unintentional walk rate hitting eighth than he does hitting elsewhere in the order.  However, most of Ianetta's time hitting eighth has come this year (and, by extension, very little of his time in other slots in the lineup has come this year) when he has posted by far the highest walk rate of his career.    It could make an interesting study for someone after the D-backs' his favorite team's post-season run ended, though.  ;-)

If we allow ourselves to be duped into viewing this possible correlation as fact, even for just a moment, we find ample reason to believe that Parra's improvement in walk rate is not purely a product of hitting eighth in the D-backs lineup for much of the season.  If his true unintentional walk rate outside of the 8-spot is close to the 7.88% mark he's posted in his 165-PA sample, that would represent a massive improvement in Parra's approach from 2010 to 2011.

To try to validate that ~8% UIBB%, let's see if there are any noticeable differences in Parra's per-pitch plate discipline metrics (FanGraphs.... thank you so much for existing).

	O-Swing%	Z-Swing%	Swing%	O-Contact%	Z-Contact%	Zone%
2009	30%	68.7%	49.2%	64.8%	90.1%	49.6%
2010	40%	69.9%	52.6%	64.8%	92.9%	42.2%
2011	38%	73.2%	52.2%	68.4%	89.9%	40.4%

For those who aren't super-familiar with FanGraphs' plate approach metrics, here's a quick tutorial on what these mean:

Swing% - Is the percentage of pitches that the hitter swung at.  O-Swing% and Z-Swing% refer to the percentage of pitches swung at that were thrown outside the strike zone and inside the strike zone, respectively.

Contact% - Is the percent of pitches that the hitter made contact with respect to the number of pitches the hitter swung at.  O-Contact% and Z-Contact% refer to the percentage of pitches that the hitter made contact with that were thrown outside the strike zone and inside the strike zone, respectively.

Zone% - The amount of pitches thrown to the hitter that were thrown inside the strike zone as a percentage of total pitches thrown to the hitter.

This trends within this table aren't as clear as those within the batted ball table, but I do still think they're there.  Here's how I interpret the data here: when Parra first got up to the big-leagues, there wasn't much of a report out on him, so pitchers approached him as they approach any other hitter, throwing him plenty of strikes and attacking him.  We all witnessed this as fans when Parra came up and raked from the get-go, getting plenty of fastballs to smack the opposite way.  However, after he had so much success in his first year and scouting reports got around about his swing-happy ways, pitchers dialed back how much they lived in the zone.

Parra was unable to adjust to the increased number of pitches outside the zone in 2010, swinging at a similar total amount of pitches, but finding that many of the pitches that used to be strikes were now dipping out of the zone or spotted a few inches outside.  In 2011, Parra hasn't necessarily dialed down his total swing quota, but what he has been able to do is re-adjust to the increased number of pitches out of the zone thrown to him, becoming more selective as pitchers have thrown him even fewer strikes.

Again, there's always the possibility that the reduced strike total has to do with hitting eighth as often as Parra has this year.  What makes me extremely encouraged among Parra's plate discipline metrics is the increase in Parra's Z-Swing%.  It's easy to argue that Parra's O-Swing% has dropped as a result of simply becoming passive at the plate and not swinging at the increased number of balls thrown his way, but that kind of passivity would result in a similar drop in Z-Swing% (and total Swing%).  However, Parra has actually increased his Z-Swing% in 2011 to a career-high total, while his total Swing% has remained fairly constant from 2010.  To me, this means that Parra hasn't dramatically changed his hitting approach with his lineup position.  Rather, Parra is simply better able to recognize which pitches are strikes and which are not.

The increased Z-Swing% also indicates that his decrease in O-Swing% isn't simply a product of waiting to get walked in the eighth spot of the lineup - he's remaining aggressive at the plate overall, so the decrease in swings on pitches out of the zone from 2010 to 2011 also looks like legitimate progress in his ability to recognize pitches out of the zone.  Additionally, since each individual pitch is a data point, one of the largest benefits of this type of data is that it ought to normalize much quicker than most batting stats for which any single plate appearance counts as at most one data point.  This means that we can be more confident that the conclusions we draw from this data aren't a product of small sample sizes than some of the pure walks per plate appearance data above.

 

Without a doubt, there have been incredible strides made by Gerardo Parra in 2011, both in his improvement offensively and in his ability to prove that his high UZR figure from 2010 was no fluke.  Best of all, perhaps, is that the guy is 24 years old.  If Cot's is to be believed - I'm not sure if it is; I don't know where, but I recall hearing that he'll be a free agent after 2015 -  the club to has control of Parra through 2016, his age-29 season, so we can expect to retain Parra through his physical prime.  For a player that prominent baseball evaluators were saying would never be an everyday corner outfielder as recently as last April, he's turned in an incredible season and looks like exactly that.