pVals are a topic of debate among pitch-level data masterminds. One side may consider them useless. Good pitches get hit and bad pitches get taken for strikes and pVals don’t explain any of that. On the other side, people like to know what actually happened. If a splitter left in the middle of the zone gets a called third strike when it probably should have been mashed for a home run, then pVals still credit the pitcher. The strikeout is what actually happened.
Keep in mind as you peruse this season’s best fastballs just that; pVals aren’t perfect. You’ll read about Chris Bassitt’s sinker and think, Chris Bassitt is a clear candidate for being drafted, but read on and you may back away from that stance. pVals help us understand what occurred, but take caution when using them to predict what will happen. Confused? Let’s just watch some GIFs.
Part one of this installment looked at four-seam fastballs and cutters. Part two will focus on sinkers and splitters.
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