from Amazon
Friday, January 18, 2008
Change in batter/pitcher approaches through the Retrosheet years
I’m looking at the out conversion rates of shortstops per ball in play, in the Retrosheet years. I grouped them by era (my standard ones that work well, which is to say 1957-1968, 1969-1981, 1982-1992, 1993-present). I further grouped them by batter and pitcher hand. Across the years, for lefty batters, things are pretty constant. When the pitcher is a lefty, the batter makes an out to the SS around 9.3% of the time. And against righty pitchers, the batter makes an out 9.0% of the time. There’s really not much change, era to era.
But, for righty batters, there’s a huge difference. Against lefty pitchers, it’s 15.3% through 1981, and 14.2% after that. And against righty pitchers, it’s 16.2% and 15.0%. I’d have to look at the out rates for the other 3 IF positions, but it seems to me that v RHH, there’s alot more balls that are hit or thrown away from the batter. Either that, or the type of RHH around since 1981 is of much different type than before then.
Anyway, I’m having fun with various WOWY changes I’m attempting. I’m trying to keep it as simple as possible, and the handedness angle, as Rally has demonstrated, is a good one to tackle.
Maybe it’s the defensive quality of the shortstops. We’ve seem the position become better offensively, so perhaps teams have been willing to accept less defense there.
Why wouldn’t this show up against lefthanded hitters then? Maybe it has to do with pulled vs opposite field groundballs.
Are 2B showing a similar effect?
Does that effect show up equally on SS who spanned the era?