As we head towards the second-half of the season, it seems like a good time to review the major players in the first half of the season and grade them according to their performance. A couple of things to note before we go into the 25 chosen ones: I'm grading on a curve, with a C basically meaning they performed at league average for their position. More recent performances are also weighted more heavily, and adjustments then made for intangibles such as expectations, salary, etc. - even at the same position, we expect more out of Drew than Ojeda, say.

If the overall marks seem somewhat high, this is because a number of players, some of whom had significant impact on team performance, could not be assigned grades. I'm being somewhat generous there, since in certain educational establishments, these would be automatic F's...

  Sick notes: Conor Jackson, Brandon Webb.
  Incomplete: Bryan Augenstein, Blaine Boyer, Alex Romero, Doug Slaten, Josh Whitesell.
  Expelled: Tony Clark, Josh Wilson.
  Transferred to another school district: Tony Peña

Basic stats for position players are OPS+ and UZR (combined across positions if necessary); for pitchers, I'm using ERA+ and WHIP. Follow me after the jump for the report-card - you'll see why it took a little longer than I thought to produce! And I expect to see it back on my desk, signed by the players' parents, by Monday morning, or else some of you will be staying after school...

Top of the class
Dan Haren, A+, 226 ERA+, 0.808 WHIP
As noted previously, Haren had one of the best first-halfs in franchise history, posting an astonishing ERA of 2.01 and an even-better WHIP. He could easily have had thirteen or fourteen victories by this stage. Yes, the BABIP is freakishly-low, and we should probably expect some regression going forward. However, there's little evidence he'll stop being among the best pitchers in the National League.

Dean's list
Justin Upton, A, 134 OPS+, UZR 8.8
Expectations were high for J-Up coming in to 2009, but I think it's safe to say that he has surpassed them all, with one of the best seasons in recent history by a player his age [only A-Rod, Griffey and Pujols have posted a better OPS+ since 1981]. And look at that UZR: while he still makes too many silly error, the metric ranks him the second-best fielder on the roster.

Doug Davis, A-, 133 ERA+, 1.440 WHIP
Perhaps the most unexpected pleasant surprise of the season is DD, whom we thought would return his usual ERA in the mid-fours. Heck, no - and the weird thing is, his BABIP is .303, so it's not as if he has been 'lucky'. Indeed, quite the opposite as far as his 4-9 W-L record goes: that's the lowest Win % of any pitcher in the past century with such a good ERA+ [since Ned Garvin, 5-16 with a 158 ERA+ in 1904]

Gold stars
Mark Reynolds, B+, 125 OPS+,  -5.5 UZR
Special K certainly stepped up his production on both sides of his nickname, tying for second in the majors for home-runs (24), but leading all players in strikeouts (123) and on pace to break his previous all-time record by 20. However, his output overall was excellent and, despite ongoing issues with his glove, he also deserves credit for speaking up and apparently becoming a clubhouse leader to many.

Max Scherzer, B+, 124 ERA+, 1.349 WHIP
Question-marks about Max's stamina seem largely to have been answered, with Scherzer going six or more innings in the majority (ten of 17) of his appearances. His strikeout rate is down a little compared to last season, but hard to complain when it's still more than a batter per inning. Perhaps most encouraging, third-time through the lineup, batters hit .221 of Scherzer, though this is BABIP-assisted.

Solid performances
Clay Zavada, B, 269 ERA+, 1.500 WHIP
A great story, Zavada's fairy-tale reached its "happy ever after" on May 21 when he made his major-league debut. But wait! There's more! He then went on to post the longest scoreless streak to open a career in franchise history. While he's doubtlessly overachieving tremendously - I don't expect him to post anything close to a 1.69 ERA in the second-half - he's a joy to watch, pitching or not.

Gerardo Parra, B-, 94 OPS+, 1.1 UZR
Called up from Double-A due to the Jackson and Byrnes injuries, he's performed pretty well. He has the best BA of any NL rookie with 200+ PAs, and trails only Colby Rasmus of the Cardinals in OPS. So far, he's certainly among the best outfielders his age (he only turned 22 in May) regularly playing the majors this year. If he could learn to hit lefties (.178 BA), he'd be golden.

Felipe Lopez, B-, 101 OPS+, 3.8 UZR
Lopez is like the super-brainy kid who cruises through tests without actually bothering to try. He always gives the impression he could do better, but really, what's the point? However, his production is pretty close to that of Orlando Hudson (OPS+ 106) and Lopez's defense - a cause for concern pre-season - is actually much better (O-Dawg's UZR is -5.3). Still, a transfer to another district may happen soon.

Stephen Drew, C+, 98 OPS+, -0.6 UZR
I'm tempted to append "Must try harder" to the grade, since great things were expected after his 2008 season (110 OPS+). He hasn't lived up to that, though I wonder if injury played a part, as he has been better since coming back off the DL (OPS .795 vs. .666). We'll be hoping for the same second-half explosion we saw last year: his current OPS is almost the same as at this point in 2008.

Middle of the pack
Jon Rauch, C+, 105 ERA+, 1.387 WHIP
The archetypal bad kid appears to have turned over a new leaf, after starting off the year looking destined for an F. From a 9.00 ERA on May 4, he has slashed that figure in half, thanks to a 2.12 ERA over 17.1 innings since the start of June. Of course, he still has a poor reputation and his previous crimes and misdemeanors will not easily be forgotten. yet there's been more good than bad from him.

Scott Schoeneweis, C, 84 ERA+, 1.600 WHIP
The dog ate Scott's homework. Actually, there are far better excuses which should be applied in mitigation of his performance. One, we needn't go into. However, his stats would be a lot better if he faced strictly left-handers: their OPS against him is .686; right-handed batters post a 1.059 OPS. It's been more or less like that since 2007, so why he ever sees righties, beats me.

Jon Garland, C, 100 ERA+, 1.500 WHIP
When he's good, he's very good, but when he's bad... In 18 appearances, he's allowed one earned run or less seven times, but has also had four games allowing six or more earned runs. Not much middle ground for Jon, though averaging over six innings per start is pretty good. Guess his performance is much in line with what we expected, given a career ERA+ of 103.

Miguel Montero, C, 94 OPS+, N/A UZR
He's like the kid who gets a pass because his brother's the quarterback, then suddenly discovers that cuts no ice with the SATs: as our backup, Montero had a not-exactly great line of 225/344/.353, teetering on the edge of a failing grade. Maybe Miggy just needed a challenge, because he has surged at the plate since Snyder went down, pulling him up to average. Keep up the improvement, please.

Chad Qualls, C, 125 ERA+, 1.179 WHIP
Normally, that good an ERA would deserve a higher mark. But since May 25th, he has blown three saves in eight chances, and the only warm feeling we get when he enters the game is if he makes us lose control of our bladders. He has fallen in with a bad crowd - that'd be the rest of the bullpen - and is staying out late and skipping classes. Worrying signs for a parent: he's better than this.

Needs improvement
Chris Snyder, C-, 90 OPS+, N/A UZR
General wisdom is Snyder is a better game-caller than Montero. Yet with Montero/Garland this year, opponents have a .676 OPS, much less than Snyder/Garland (.922). Maybe Chase Field isn't the problem? [Haren pitches better with Snyder, Davis is catcher-neutral, and Scherzer also seems to prefer Miggy] At the plate, Snyder still walks a lot, but a .224 average is his worst since 2005.

Esmerling Vasquez, D+, 93 ERA+, 1.618 WHIP
Interesting reverse split for the young right-hander: lefties hit .200 off him, while righties hit .343, the opposite of what we would have expected, though all three home-runs allowed were by southpaws. However, it's could well just be BABIP, where his split is .426/.200, so I'd expect things to even out over time. Too many walks - 15 in 29.2 innings - doesn't help.

Leo Rosales, D+, 89 ERA+, 1.189 WHIP
Weird numbers for Rosales: opponents hit .227 with only one homer,. Basically, he had one bad inning, where he walked four of five batters, leading to three earned runs - outside of that, his ERA was 3.78, including 3.1 hitless frames in the 18-inning marathon against the Padres. While that's more an explanation than anything else, might he be worth another shot?

Juan Gutierrez, D, 90 ERA+, 1.594 WHIP
Turned 26 yesterday, and while his raw 'stuff' continues to be there (45 K's in 42.2 IP), his ability to control it isn't (21 BB). He has also been a fly-ball pitcher: his GO/AO ratio is the worst on the team at 0.62  - league average is 1.10 - as is a 24% line-drive percentage. That's not generally a sign of success at Chase, but he has somehow kept the ball in the park, with just one homer this season. Could go either way.

Augie Ojeda, D, 56 OPS+, 1.9 UZR
While we can't fault Augie's effort, and some aspects of his game, such as his defense, are credible enough, the truth is he has been badly overmatched at the plate this season. His career OPS+ is only 63 and he has fallen short of that, hitting only .221 with a single home-run. At age 34, I've a feeling the next few months could be Augie's last hurrah on a major-league roster.

Ryan Roberts, D-, 76 OPS+, 1.0 UZR
I don't know what Roberts had for breakfast on May 9, but whatever it was, worked. From then through June 2, he was on fire, hitting .438 (21-for-48). Then, as soon as it began, it ended, and he went 3-for-40 before being called to the principal's office and told he was being held back a grade. It was nice while it lasted, but overall, you could see why he still qualified as a rookie at age 28.

Fail
Chad Tracy, F, 72 OPS+, -1.5 UZR
Tracy has not been the same man after coming back from knee surgery last May. Prior to it, his career OPS+ was 105 - since then, it's 79. The odds of the team picking up the $7m option for next season look pretty slim, especially as he's strictly platoon fodder (career OPS vs. LHP: .619). Chalk up another victim to the Curse of the Contract Extension: see also the next two 'scholars'.

Chris Young, F, 68 OPS+, -2.9 UZR
Despite recent signs of life - his OBP is .390 since June 1 - the season's batting average still sits resolutely beneath the Uecker line. Since the game was integrated in 1947, only five qualifying players have been sub-.200 over a full season (most recently Rob Deer, who hit .179 in 1991); we don't want CY to be #6. UZR thinks his defense has fallen off this year too - he was +0.5 in 2008.

Eric Byrnes, F, 63 OPS+, 10.7 UZR
No, that UZR is no mistake: by it, he's the best fielder on the team. However, it's almost irrelevant when his OPS+ barely beats out Ojeda, and Eric earnd almost $11m more [autograph shows and TV residuals not included]. That ranks Byrnes 235th among the 241 major-leaguers with 200 PAs this year, and his 22% infield fly rate would be 4th among qualifying hitters, if he had enough playing time.

Billy Buckner, F, 53 ERA+, 1.770 WHIP
Yusmeiro Petit, F, 57 OPS+, 1.758 WHIP
We'll give the third member of the Triple-Headed Beast of Webb Replacement Suck, Bryan Augenstein, a pass - he was called up from Double-A, so his struggle was no surprise. No such excuse for these two: the team went 3-11 in their fourteen combined starts. We would probably have had better results asking Webb to pitch left-handed. Get well soon, Brandon. Please...