You’ve heard me yammering about pitch-type peripherals for two years now, and we’ve made some advancements along the way. We established some good pitch-type peripheral benchmarks, and we took a first look at properly weighting each pitch. We’ve started to get a sense of how these things interact when it comes to the shape and speed of pitches. We’re making progress.
It’s worth stepping back and figuring out what the aim is at this point. Because we aren’t trying to rank the best starting pitchers overall, really. We’re trying to find undervalued pitchers before the market realizes that they’re good. So we have to move in the smallest possible samples. And we want to have a list of great pitchers that has some weird names on it as well. Those names, we hope, will soon start to make sense.
So, to that end, I’ve taken each pitch type and looked at only those pitchers that have thrown 100+ in each of those types. I’ve summed the ground-ball and swinging strike rates for each pitch, and then found the standard deviations. I’ve given each pitcher a z-score for his ground-ball rate and swinging strike rate on each pitch type. Then I’ve summed the z-scores for each pitch type, and then for each pitcher.
What we should be looking at is an Arsenal Score. With this way of looking at things, it’s possible to have one dominating pitch and still score well. Or a group of lesser pitches that are all positive.
What we haven’t done yet is nail down what the smallest sample for each pitch is. Or how to weight the pitches. Or how to weight the whiffs versus the grounders. So this may look different once we weight each pitch differently, and if we find a way to weight grounders and whiffs more correctly.
But at least we have a first attempt at it here.
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