An Astros' fan on another site pointed out last night that the Astros surrender a lot of runs in the 7th inning. So, let's look at the Astros' run prevention over the course of a game. First, total runs allowed in each inning:
While it is true that the Astros give up the second most runs in the 7th, the really noteworthy number is the 15 runs allowed in the first inning. Clearly, the 1st, 5th, and 7th innings have more runs allowed than the other innings.
Now let's look at balls in play (BABIP) and OPS+ stats by inning.
(BABIP / OPS+)
1st. .413 161
2d .280 96
3d .298 76
4th .353 77
5th .347 96
6th .256 90
7th .377 174
8th .280 77
9th .189 94
Clearly, the 1st and 7th inning are the worst inning based on opponents' OPS and balls falling in for hits. The 7th inning allows the opponents to ring up a Pujols-like slugging percentage of 1.024. Astros' pitchers have also given out 11 bases on balls in the 7th inning---by far the worst inning for walks. The OBP in the 1st inning is .451 and .444 in the 7th inning, which are Barry Bonds' like numbers.
Are batters figuring out the pitchers as they get more turns against them? The numbers don't support that propsition. OPS+ by first, second, and third plate appearance against the pitcher:
So we have a first inning and seventh inning problem. Why? Well the 7th inning problems is primarily due to the inability of starters to pitch effectively into the 7th inning. At that point, the opposing team gets into the Astros middle relief. Middle relief is the weakest part of most teams' pitching staffs. And the Astros' bullpen has been less effective than expected. When Astros' starters have attempted to pitch deep in games, their effectiveness has diminished. The OPS+ for pitches 25 - 100 has been between 65 and 89, but the OPS+ for 101 or more pitches has been 122. The overall OPS+ allowed in the 7th inning last year by the Astros was 96, by the way.
This indicates to me that Cecil Cooper may be pushing starters to go longer than they can at the current time, and that the middle relief performance needs to improve. Those two things are likely interrelated. Hopefully, getting Brocail back, perhaps this Sunday, will bring some order back to the bullpen. However, given the age of some of the Astros' starters, the middle relief role may be more important than ever for the Astros. That situation bears close attention.
I'm not sure why the first inning has been bad for Astros pitchers. Based on watching the games, my impression is that they have seen more than the typical number of unlucky hits, and the .400+ BABIP in the first inning supports that view. There are also the usual suggestions, like making sure the starting pitchers are adequately warmed up. This isn't a new experience for the Astros, though. The Astros' pitchers had an OPS+ of 134 in the first inning last year. My recollection is that the Astros had some disastrous first innings in 2008, which contributed to that result. However, allowing runs in the 1st is always a bad way to start the game, and generally puts the pitcher in a position where he is behind in the score, which can lead to a "pitching from behind" mindset. Maybe the starters need to try some Zen or yoga type exercises before the game starts...or just about anything to get a better start.