Are foul balls a skill? Do they lead to better outcomes? Should all hitters have a two-strike approach?
Let’s try to answer some of those questions the best we can.
If fouling a ball off was an easily measured skill — if percentage of balls fouled was a good measure of that skill at least — then you’d expect the skill to show through most years. Strikeout rate, for example, is fairly decent at measuring your ability to make contact. Strikeout rate stays fairly stable — you could use shorthand to say that almost 90% of your strikeout rate next year is described by your strikeout this year.
Foul percentage doesn’t work that way. Your foul percentage this year describes about 40% of the variance in your foul percentage next year. That makes foul percentage more unstable than batting average, batting average on balls in play, or your rate of doubles per plate appearance. Brian Roberts was 11th in baseball foul percentage this year, he was barely above average in 2013. So it goes.
With a phone full of pictures of pitchers' fingers, strange beers, and his two toddler sons, Eno Sarris can be found at the ballpark or a brewery most days. Read him here, writing about the A's or Giants at The Athletic, or about beer at October. Follow him on Twitter @enosarris if you can handle the sandwiches and inanity.