Here is a quick look at how I would grade each Astros player's results so far this season.
We'll start with the position players. I'll give the grade, wins above replacement (WAR) calculations (according to fangraphs and baseball reference), and brief thoughts on performance. I went with a 100 plate appearance minimum.
A+ Justin Rug . . . oops, we traded him, didn't we? (I'm actually fine with the trade and am glad to see Ruggiano succeed).
A- Jed Lowrie (2.6, 2.1) Great production and solid fielding at shortstop; .254 batting average may just be unlucky.
B+ Jose Altuve (2.0, 1.7) Strong hitting and baserunning, with improvement needed in plate discipline and fielding.
B- Jason Castro (1.0, 0.8) His.709 OPS at the catching position in this offensive environment is impressive; needs to make improvements in his defense.
B- Justin Maxwell (1.0, 0.9) He provided much needed power and adequate defense when he was in the lineup; 36% K rate suggests that ongoing success will be difficult to achieve.
C+ Chris Johnson (0.9, 0.5) After a hot 2010 and cold 2011, this season seems to reflect his natural level offensively, with solid .275/.321/.405 numbers; his defense is a significant liability at 3B though. Did you know that CJ has a higher walk rate than Altuve?
C J.D. Martinez (0.7, -0.4) He does a good job driving in runs, but better offense than a .718 OPS is needed from a corner outfield position. Baseball Reference actually has him at lower than replacement level, but that seems too low.
C Brian Bogusevic (0.7, 0.5) His offense this year is in line with his minor league numbers and confrims that last season's MLB numbers were an aberration; his defense is strong, but he doesn't produce enough at the plate (.636 OPS) for a (mostly) starting outfielder.
C Carlos Lee (0.2, -0.1) At least his batting average and contact rates were consistent, but lack of power, speed, or defense made him expendable. We were lucky to get C+ prospects in exchange for him.
C- Chris Snyder (0.1, -0.2) Decent walk rate, but weak batting average and less than expected power. But backup catchers don't typically set the league on fire.
D+ Jordan Schafer (0.4, -0.3) After a brief strong start, his offense and defense has suffered; attitude issues add to concerns about his value to the team.
D- Matt Downs (-0.5, -1.1) A disappointing season for sure; his only bright point was his occasional power (5 home runs).
Incomplete: Gonzalez, Bixler, Buck, Moore, F Martinez, Dominguez.
Next is pitching, with a 20 IP minimum:
B+ Wandy Rodriguez (114.2 IP, 3.38 ERA) Only 25 walks in 114.2 innings - that is impressive. Averaging over 6 innings per start is handy too.
B- Brett Myers (29.2, 3.34) He has 14 shutdowns to 5 meltdowns, which is better than any of his bullpen mates but not in the same ballpark as elite closers in the MLB.
B- Wilton Lopez (32.1, 2.51) 4 walks in 32.1 innings has done the trick. He has 11 shutdowns to 6 meltdowns, which is too many meltdowns for him to be graded too much higher.
C+ Brandon Lyon (33.1, 3.24) A strong 35 K's to 8 BB's is counteracted some by a lukewarm 7 to 5 shutdown to meltdown ratio.
C+ Lucas Harrell (102.2, 4.56) Some of the advanced stats say that he has been better than his ERA has shown. Also, he is averaging 6 IP per start.
C+ Dallas Keuchel (25.2, 2.45) Sure, the numbers don't appear to be sustainable for when he gets called up again (13/10 BB/K), but whether it was thanks to luck, his fielders, or his saavy, he got results in his brief MLB stint.
C Wesley Wright (24, 4.13) 5 shutdowns and 6 meltdowns. Color me unimpressed.
C Bud Norris (86, 4.71) This has been a disappointing season for Norris. He averages fewer than 6 innings per start and has given up too many walks (32) and home runs (13).
C- J.A. Happ (98, 5.14) Similar profile to Norris, but a little less successful overall - good K's, but struggling in other areas.
D+ Jordan Lyles (62, 5.08) The numbers don't show many positive signs. I am hopeful about his future, but this is a grade for 2012 so far.
D Rhiner Cruz (28.1, 6.35) Shows flashes of potential, but is definitely still a work in progress.
D David Carpenter (29.2, 6.07) Not a lot to like here.
F Fernando Rodriguez (32.2, 6.61) He can strike people out (34 K's), but like others on this list, that doesn't get the job done on its own. Are you surprised that he has 10 meltdowns in so few innings? I didn't think so.
Incomplete: Weiland, Abad, Del Rosario, A. Rodriguez, Cedeno.