Hitters' well-hit average was lowest on pitches Down & In (.211) and Down & Away (.257). I like running it by Well Hit of Strikes. That is, if we throw a strike in that particular locaiton, how many of those are well-hit? The answer is .077 (8%) for Down & In, and .081 for Down & Away. Compare that to Middle / Middle, which was .272 (27%).
Command is key. There's no doubt about it. There are other factors too, of course. Count is a big one. We have interesting data there too. Pitch type is another.
Well-Hit of Fastball Strikes was 15%, and Non-Fastballs, 10%. These are our team numbers from 2005. It varies from pitcher to pitcher.