FiveThirtyEight: How Baseball's New Data Is Changing Sabermetrics

[weams]

I'll move this after folks get to see it in the main thread.

http://fivethirtyeight.com/features/how-baseballs-new-data-is-changing-sabermetrics/?ex_cid=538twitter

Judging from the long shadow it cast at the conference, Statcast might be the chief disruptor of Sabermetrics 1.0. Daren Willman of MLB Advanced Media and Mike Petriello of MLB.com demonstrated the power of the system to monitor factors as varied as the spin on Jake Arrieta's curveball and Kevin Kiermaier's defensive range. Sabermetric evaluations of defense, in particular, may benefit greatly from Statcast, as analysts will be able to more precisely measure all aspects of defensive play - from a fielder's first step to his maximum range and the velocity of his throws.

For example, during the first wave of sabermetric defensive measurements, shifts especially confounded our ability to home in on a player?s true fielding skill. Statcast addresses that flaw by measuring the positioning of every fielder before each pitch, and when that information eventually becomes public1 it will undoubtedly reshape our defensive metrics.

Baseball Info Solutions analyst Scott Spratt offered one potential transformation at SABR, with a new model for integrating shifts into fielding stats such as Defensive Runs Saved. In situations where several fielders could make a play on the ball because of an extreme shift - which places several players on one side of the field, making it difficult for current metrics to apportion individual credit for a defensive run saved - the model gives some of the credit to the whole team. According to Spratt, the Tampa Bay Rays (not surprisingly, one of the most sabermetrically savvy teams in baseball) led the league in these separate, team-based runs saved on shifts last year

Another of the conference's talks dug deeper into Statcast's exit velocity information. Most notably, Brian Cartwright, creator of the Oliver projections at FanGraphs, discussed how exit velocity alters our view of defense-independent pitching statistics. DIPS theory is one of sabermetrics' most treasured counterintuitive insights - the idea that pitchers bear no responsibility for the results of balls in play - but Cartwright showed that a ball?s velocity off the bat is partly attributable to the pitcher (even if the batter deserves more of the credit). He also broke down exit velocity by angle and explained that even fly balls allowed by ground-ball pitchers travel at a lower angle, making them more difficult for the defense to field. For instance, Andrew McCutchen and his fellow Pirate outfielders were notably harmed by their ground-ball pitching staff's tendency to allow these low screamers.

[Frobby]

Interesting, and not particularly suprising. I've said many times that the "advanced" defensive metrics will be considered very primitive, and even misleading, once the statcast info is applied. My guess is it will take a few years and an iterative process to really apply it well. I only regret that the analysts won't be able to go back more than a year to show how wrong some of the defensive measurements were.

[weams]

Interesting, and not particularly suprising. I've said many times that the "advanced" defensive metrics will be considered very primitive, and even misleading, once the statcast info is applied. My guess is it will take a few years and an iterative process to really apply it well. I only regret that the analysts won't be able to go back more than a year to show how wrong some of the defensive measurements were.

I know. I love the statcast though.

[Can_of_corn]

Of course it is changing things, the groups advocating this sort of thinking welcome new data.