In baseball, you don't know nothin'.
--Yogi Berra

Another bad outing by Roy Oswalt last night caused him to say in frustration that he is pitching like a minor leaguer.  For fans, the question is "what happened to the real Roy Oswalt?"  You know, the one that dominated opposing hitters.  For manager Cecil Cooper, the frustration is evident from his quotes here:

"Right now, I don't know where to go with Roy because I've never seen him struggle this much,"  "You've got to go back and look at tape and figure things out because I've never seen him struggle like this.

"He's not making pitches, and when he makes mistakes, the ball is over the middle of the plate and they're hitting them pretty hard. There were also some good ones thrown in there (Thursday), too."

"Right now, I don't know where to go with Roy because I've never seen him struggle this much," Cooper said. "You've got to go back and look at tape and figure things out because I've never seen him struggle like this.

Neither the Astros nor Oswalt is blaming injury.  My natural suspicion is that Oswalt is still showing the effects of the hip/groin/whatever problem which surfaced in the game at Texas.  That's the game in which Oswalt and Cooper had a "misunderstanding" which put him back on the mound to start another inning after he was hurt.  Apparently Oswalt has been hit by liners in the same spot twice, aggravating the injury.  (The first time was on opening day; presumably the second time was in the Rangers' game.)  I can imagine the possibility that such an injury might seem to feel "better," but still have an effect on the pitcher's delivery.  If that's not the problem, then perhaps it is a mechanical issue, and we can only hope that Dewey Robinson and Roy figure this out as quickly as possible.

Prior to the Rangers' game, Roy Oswalt was showing marked improvement in his pitching and appeared to be on verge of returning as the old Roy Oswalt.  This improvement period was from April 16 - May 12, when Roy notched all four of his wins.  During that span, he pitched 7 innings three times, 6 innings two times, and 8 innings once (May 12 vs. SF).  His ERA steadily declined during that period from 6.65 to 5.05.  Due to the Rangers and Phillies games since then, Oswalt's ERA has risen back up to 5.61.  The fact that Oswalt was showing such steady improvement prior to the Rangers' game leads me to discount any notion that Roy's skills have declined precipitously.  That also fuels my suspicion that some type of injury in the game at Texas is at least partly responsible for his recent problems.

I don't really buy into the idea expressed by some that Oswalt is "in decline" and can no longer pitch at a high level.  Sure, at his age, some of his skills may be in decline, but the effects are likely to very gradual and perhaps even imperceptible as he adjusts his pitching style.  According to fangraphs, Oswalt's fastball velocity has declined from 93.1 mph to 92.3 mph from 2005 to 2008.  But the decline in velocity seems to be very gradual, with his 2008 velocity only 4/10th mph lower than 2006 and 2007.  Oswalt also has been relying less on the fastball each year since 2005; so far in 2008 he has thrown 60.0% fastballs, compared to 69.8% in 2005.

The lower percentage of fastballs is an interesting context for Oswalt's stated plan, after Thursday's game, to get back to his basic pitches, the fastball and curveball. Both Roy and his catcher, Brad Ausmus, believe that he should rely on the pitches "which got him here."

Oswalt normally thrives at Minute Maid Park: his ERA at MMP last year was 1.91.  But MMP has been a house of horrors for him in 2008.  His ERA at MMP is 6.68, compared to 4.85 on the road.  A big reason for that is the home run.  Although he has played one more road than home game, he has given up 11 of his 15 home runs at MMP.  Certainly that home/road split has to be cleaned up if Oswalt is to be the Astros' ace.

Over the last few games, Oswalt's groundball percent, which stood at 51% for much the year, has declined, now at 47.8%.  That generally isn't a good sign.  Groundballs are a particularly good idea, considering that almost 1 in 4 flyballs off Oswalt are ending up as HR souvenirs.  I am guessing that Oswalt is getting more pitches up in the zone than normal.  Another interesting stat: hitters apparently know what Oswalt is going to do on the first pitch.  Batters are hitting .421with a 1.137 OPS on Oswalt's first pitch.  Like most pitchers, Oswalt tries to get ahead with strike 1, but it sure seems like he is doing something which is too predictable.

I'll end with a final split stat which is significant.  Lefthanded batters are killing Oswalt.  LH batters have a batting average of .348 and an OPS of .985 against him. The batting average is nearly 100 points higher, and the OPS about 200 points higher, than the numbers for RH batters.  Lefthanders normally hit better than righthanders against Oswalt, but the margin is ordinarily much smaller.  That makes me wonder if something in his delivery or approach has allowed lefthanded batters to figure out his pitches.