How a Starting Pitcher Performs When Immediately Facing the Same Lineup
Today’s article has been a couple of weeks in the making. I know it came up when one of my co-managers, Fred Zinkie, asked how much a pitcher’s performance changes if they immediately reface the same team. I don’t remember the pitcher or team involved but I didn’t know the answer so I’d find it out. The obvious answer is sure, a pitcher will be worse. It makes sense that the team that just faced him will have some familiarity. Two questions do come up though. First, how much does the pitcher’s performance degrade in the second matchup? Next, if there is a familiarity factor, how long does it take to go away? After examining the data, a small factor exists and quickly disappears.
Simply, this is one of the noisiest, possibly biased studies I’ve ever worked on. First, a starter usually doesn’t see a team right away since schedules have quite a bit of variation in them. This limits the sample size. Second, the data is clumped at five-day multiples because the starters need rest. I begged for a possible solution on Twitter but no solution was found. Even with the limitations, I forged ahead with some workable results. Read the rest of this entry »