(Photo by Juan Salas/Icon Sportswire) Welcome back to my “Plate Discipline” series. This week, I’m trying something new and exciting – broadening the scope of my analysis by incorporating StatCast data. Previously, contact management was a completely missing element in my ranking system, which led to some strange results and a lot of double-checking other sites to figure out why. StatCast is the best thing we’ve got right now to measure quality of contact, so my goal with this is to make my rankings more comprehensive of a pitcher’s full skill set, and help identify other types of luck beyond just strikeout rates. I’m open to feedback, so if you have any thoughts about the new ranking system please let me know in the comments! The specific metric from StatCast that I’ve chosen to incorporate into my rankings is xSLG. The answer is simple, but twofold: 1) I wanted this to capture “power luck”.
Free download style keyboard yamaha psr s970. This should cover luck factors like ballpark dimensions, weather conditions, and outfield defense. If a pitcher has given up many “cheap” homers relative to league average, they would be considered unlucky, and vice versa. 2) I wanted this to be completely independent of strikeout rates, which are covered already by the PD metrics. XwOBA would be the other option here, but that does include strikeouts (and walks) so I went with xSLG.
The method I used to update my scoring system is as follows: 1) Take the inverse of the xSLG (1-xSLG) because for SLG, a higher number is bad for the pitcher. We want a higher number to be good. 2) Multiply this by 1.5. This brings it to roughly the same level as PD scores, with almost all pitchers falling between 50% and 100%.
Just a handful of the top pitchers can barely top 100%. 3) Add the PD score to this number, and divide by two to bring the number back to the 100 scale. You may be asking – “Why should plate discipline and xSLG have equal weight?” and that’s a great question. For starters, in the MLB in 2018, strikeouts and walks compose just 31% of plate appearances. The other 69% end with a batted ball, so it’s easy to see that contact management is very important.
I considered giving xSLG the full 69% weight, but I wanted to apply a significant discount for two reasons: 1) Going back to the premise of why we care so much about plate discipline metrics in the first place, strikeouts are just the most reliable method of getting outs. Managing contact is great, but depending on this can be a bit more risky for a pitcher. I want to make sure my rankings reflect that.
2) This is for fantasy purposes, and strikeouts are still a fantasy category. A strikeout is just worth more than other outs for fantasy purposes, so I didn’t want to make all outs completely equal. With that out the way, here is the new-look data table. Data is through Tuesday May 22. So basically – Kluber has this reputation for being bad in the early goings, but then picking up steam over the season. He’s done that this year too, only he got luckier than usual, so it didn’t really affect his ERA.