It is frequently observed that, at least anecdotally, some starting pitchers are prone to immediately giving back in the next half inning a lead their offense has just given them. On the current roster, for example, John Danks gets this criticism. Often it is coupled with questions regarding the make-up of a player. But those explanations are usually facile.
We may now have a theory that is backed up by at least some evidence. An offense that accumulates runs in a given inning usually has a longer inning because, of course, scoring runs takes longer than, say, a single and three outs. So that team's pitcher is sitting for a longer period than usual between innings.
When is another time that a pitcher sits? When he's the away starting pitcher. Both starting pitchers warm-up in the bullpen before the start of the game. They then both saunter to their respective dugouts. After the National Anthem, the home pitcher comes out to start the game. The away pitcher has to wait for his team to make three outs.
Over the years, the home team has an advantage in the first inning when it comes to the team’s pitchers throwing more strikeouts and allowing fewer walks. Part of the advantage can be attributed to the home pitcher having less time to cool off. The longer the pitcher sits, the slower they seem to throw when they finally take the mound. While the velocity loss from sitting in the dugout does not explain all the difference in strikeout and walk rates, it is a factor. Additionally, the drop off is larger for some pitchers than for others.
Regarding that drop off:
Here are the 11 pitchers who have seen a one mile-per-hour-or-more drop in velocity between throwing in the top of first inning compared to the bottom of the inning (2013 data, minimum 1,000 fastballs thrown)
John Danks' (already injury-induced depleted) fastball average 89.3 MPH in the top of the first but drops to 88.1 MPH in the bottom of the first.
This obviously directly applies to first inning issues in away games. But the length between bullpen warm-up and pitching in the bottom half is also longer than the "usual" between innings break for a pitcher and is akin to the break when a pitcher's offense spends more time on the field, such as when they're scoring runs.
The proposed fix for these first inning foibles is to just leave the starting pitcher in the bullpen and then have him come out when the bottom half of the inning starts. That's not really practical between innings. But maybe the White Sox should consider some way to keep Danks "warmer" during the (currently minimal) half innings when the offense spends a lot of time batting. This certainly warrants a deeper analysis of John Danks' performance during short breaks versus long breaks.