SABR Analytics: New Takes On Batted-Ball Profiles, Pitch Framing

The Society for American Baseball Research hosts its fourth annual Analytics Conference in Phoenix this week. According to SABR president Vince Gennaro, the conference exists to assemble the thought leaders in the field of analytics to discuss topics important to the game. The three-day event includes nearly a dozen research presentations as well as moderated panels with players, general managers, player-development staff and broadcasters.

PHOENIX--Projection systems that forecast batter performance might be able to take a cue from the scouting community and its focus on tools-based evaluations, rather than rely so heavily on past results.

This according to Baseball Info Solutions president Ben Jedlovec in his presentation entitled "Trajectory-Based Hitting and Pitching Statistics," in which he made the case for so-called defense-independent batting statistics, or DIBS.

At the root of his assertion is the observation that, through use of the BIS batted-ball timer, a batter's groundball velocity, flyball distance and flyball hang time all stabilize after, respectively, 95 groundballs, 55 flyballs and 35 flyballs. (To review initial findings from the batted-ball timer, please see the review of the BIS presentation from 2013.)

Given those low batted-ball thresholds and how strongly Jedlovec's tailored DIBS metric correlates with in-season production (as measured by batting runs yielded from linear weights), he said it makes more sense to forecast rest-of-season performance using in-season DIBS results rather than historical precedent.

Furthermore, the DIBS metric correlates more strongly with a player's production the following season than it does with his current campaign, thus its potential utility as a forecasting tool. Jedlovec used two player examples to illustrate his point, but before delving into those case studies, let's pause to review the DIBS framework.

The DIBS metric, as explained by Jedlovec, factored eight primary input points for all batters from 2010 to 2014, those inputs being batted-ball location, groundball velocity, flyball distance and flyball hang time as well as each batter's handedness, speed, power and park-factor adjustment. Now that the level of detail inherent in DIBS is apparent, we return to our regularly-scheduled programming.


The inputs that determine a batter’s defense-independent batting statistics, or DIBS (Credit: Baseball Info Solutions)


Brewers catcher Jonathan Lucroy broke through in a big way in 2013, coming to the plate 580 times and hitting .280/.340/.455 with a career-high 18 home runs. His effort produced 10.4 batting runs (BR) for Milwaukee. However, the DIBS underpinning of Lucroy’s 2013 performance was worth 21.4 BR after looking under the surface at his batted-ball profile to normalize his hit rate and distribution of extra bases.

Lucroy took his game to another level in 2014, just as DIBS foretold, when he contributed an actual 24.4 BR by hitting .301/.373/.465 with a National League-leading 53 doubles.


Jonathan Lucroy’s batted-ball output in 2013 suggested bigger things were possible in 2014 with better luck (Credit: Baseball Info Solutions)


Going in the other direction, shortstop Starlin Castro contributed 8.7 BR to the Cubs in 2012, when as a 22-year-old he hit .283/.323/.430 with 14 home runs. His future appeared bright, but only on the surface. DIBS estimated that Castro overachieved by some 16 hits in 2012 and that, in fact, his BR total should have been -7.0.

Sure enough, Castro’s surface performance regressed in 2013, when he batted .245 with an adjusted-OPS+ of just 73, an effort that produced -22.7 BR. His underlying batted-profile suggested his performance would improve with better luck, for DIBS assessed him at "just" -16 BR, and Castro rebounded to produce a career year at the plate in 2014, when he made his third all-star team.


Starlin Castro’s underlying batted-ball profile in 2012 did not support his .283 average or production, which cratered in 2013 (Credit: Baseball Info Solutions)


Jedlovec argues that batted-ball profiles could be used as the basis for reliable in-season projections based on the stability of batted-ball data--even in smaller samples--when compared with systems that rely only on batting results as the basis for prognostication.

Who Is Responsible For A Called Strike?

BIS researchers Joe Rosales and Scott Spratt gave an encore performance of their presentation that reapportions credit for called strikes to multiple parties, rather than overstating the value contributed only by the catcher. They first unveiled their research at the MIT Sloan Sports Analytics Conference two weeks earlier.

Four different parties have a hand in determining whether a pitch is called a ball or a strike: the batter, the pitcher, the catcher and the umpire. Where past efforts to quantify the value of pitch-framing have awarded all credit to the catcher, the BIS team found that, indeed, the catcher is the most influential party, but the second-most important variable in the ball/strike equation is not the pitcher or the batter. It’s the home-plate umpire.

Catchers and umpires registered the highest positive and negative totals on the Strike Zone Plus/Minus scale devised by BIS, with Mike Zunino (16), Hank Conger (16), Miguel Montero (16), Jonathan Lucroy (14) and Buster Posey (11) leading the way in terms of contributing runs saved in 2014 via framing borderline pitches for called strikes. Dioner Navarro (-17) brings up the rear.

Umpire Bill Miller (16) paced all umpires in calling the most pitches outside the zone as strikes in 2014, and it’s not an isolated incident. He regularly ranks in the No. 1 or 2 position, according to BIS.

Rosales and Spratt concluded their presentation by extolling Lucroy for his elite-level framing ability, saying it makes up most of the ground he loses to seven-time Gold Glover Yadier Molina when it comes to fielding bunts and throwing out baserunners. Furthermore, a top pitch-framing catcher can be worth up to 1.5 wins to his team based only on racking up extra called strikes, according to the Plus/Minus metric, making it one of the more undervalued assets in the game.