Thursday, March 04, 2021
Infield Defense OAA, Iteration 2
In our first iteration of Infield Defense OAA (Outs Above Average), we looked at all the fully-tracked plays from a ball and player perspective. Since the metric is based on a time/distance model, what we call the Intercept Model, it required the ball and fielder's paths to cross.
In this next iteration, we are able to do a little bit more. We can extend the trajectory of the tracked ball until it crosses paths with a fielder. This helps us increase the sample, especially on the previous version of the tracking system, where the tracked ball would have been a foot or two short of the fielder's center of mass, and may not have been part of the iteration 1 set.
All in all, with the additional plays, the spread in OAA gets wider by a factor of 1.3 times. Here's a chart showing the before/after of Infield OAA, for the aggregate of 2017-2020. As you can see, the top dozen players are unchanged in terms of who the fielders are. What changes is their ordinal rankings. Nick Ahmed is number 1 in either version (from +53 to +64 OAA). Andrelton Simmons and Francisco Lindor swap places between 2nd and 3rd. Arenado is 4th in either version (+33, +48). Baez, Russell, Chapman leapfrog each other in 5th through 7th. And so on. After accounting for the change we’d expect simply by having 30% more plays, 90% of the change in OAA was within 5 outs. In addition, we were able to get the model to handle the 2016 data, which puts it in line with the 2016 Outfield OAA from Catch Probability.
Since the model itself did not change, but rather simply adding extra plays, then this is what we would have expected. We still have further enhancements in the works, but those would have even less impact than this iteration. That impact will be on the periphery, but at the same time, will add even more accuracy.
Recent comments
Older comments
Page 1 of 151 pages 1 2 3 > Last ›Complete Archive – By Category
Complete Archive – By Date
FORUM TOPICS
Jul 12 15:22 MarcelsApr 16 14:31 Pitch Count Estimators
Mar 12 16:30 Appendix to THE BOOK - THE GORY DETAILS
Jan 29 09:41 NFL Overtime Idea
Jan 22 14:48 Weighting Years for NFL Player Projections
Jan 21 09:18 positional runs in pythagenpat
Oct 20 15:57 DRS: FG vs. BB-Ref
Apr 12 09:43 What if baseball was like survivor? You are eliminated ...
Nov 24 09:57 Win Attribution to offense, pitching, and fielding at the game level (prototype method)
Jul 13 10:20 How to watch great past games without spoilers