Sunday, February 16, 2014

MLB Instant Replay Game Theory and the Delayed Debut

MLB's expanded video instant replay system will not debut in Australia with the Dodgers-Diamondbacks opening series March 22 and 23 because the Sydney Cricket Ground presently does not and will not have the requisite cameras or technology in place.

Instead, MLB's replay challenge system will make its first appearance a week later, March 30, in San Diego as Los Angeles travels to Petco Park for its 2014 United States Regular Season opener against the Padres.

The delay was confirmed by Dodgers Manager Don Mattingly, whose Dodgers have not yet had a comprehensive team or coaches' meeting regarding expanded instant replay and the associated challenge system.

Likewise, Arizona Diamondbacks president and CEO Derrick Hall succinctly stated, "The two games in Australia, we will not have replay." Well, at least in part. The 2008 local instant replay system established for use with home run boundary calls will travel to Australia with the NL West foes. Hall discussed replay as part of an interview with Arizona Sports 98.7 FM and looked forward to being able to show replay of close plays on the Chase Field video board without worrying about fines from the Commissioner's Office: "There were times where we got fined by Major League Baseball because we showed something we weren't supposed to show...Now we're able to show those replays."

Meanwhile, baseball statisticians and sabr scouts have been considering strategy for the new system—with just one challenge apiece (two if the first is successful), how should replay and challenges be used in advance of the 7th-inning manager's challenge deadline?

The statistics indicate that a significant majority of foreseeable challenged plays will result in an upheld call—replay will only overturn around 20% of them. Data suggests a missed call every five games played, or about three per day of full activity (15 games between the 30 MLB teams).

The conventional wisdom—which is mostly speculation at this point—tends towards throwing the metaphorical challenge flag earlier rather than later. For instance,

>> "You don't want to waste a challenge." - Cubs Manager Rick Renteria;
>> "Managers should just throw that flag for any close play, the first time they see one." - BP's Dan Brooks

Brooks and fellow Baseball Prospectus author Russell Carleton continued, "Since there's essentially no cost for missing, any time managers see a challenge opportunity, they should take it."

It all comes down to game theory. On average, we anticipate 0.20 missed calls per game; the likelihood of a successful challenge across any given game therefore, in the grand scheme of things, is low. Therefore, if any single play stands any chance of being overturned via instant replay review, it should be challenged. Confounding variables such as losing a timeout (NFL, NCAA Football) are wholly irrelevant as the only consequence is losing the ability to challenge another close call prior to the seventh inning when umpires take over the challenge initiation responsibility.

Given the great minuscule nature of replay calls, could we potentially see an interaction with team status as home or away? Because the visiting team tends to receive, all else equal, approximately 2-5% fewer advantageous calls than the home team, could visiting teams initiate most challenges or, alternatively, could a team's status as the visitor indicate, all else equal, a greater propensity to challenge a call?

To another end and in regards to zero sum game theory, could teams have a propensity to challenge more plays officiated by an umpire perceived as unreliable than an umpire perceived as accurate (e.g., would a CB Bucknor v Jim Joyce replay statistical analysis show a significant disparity of plays challenged—and upheld or overturned?)?

Furthermore, replay is presumably "better" than the umpire when, for instance, the replay angle is better than that of the onfield umpire. Because it is rather improbable to prove a negative in a sport that follows the "clear and convincing evidence" standard (e.g., not de novo or on its own merits), certain challenges will be more successful—presumably—than others.

The general principle is that instant replay can prove that, for instance, a fair ball actually was foul but not that a foul ball was actually fair—this isn't to say such a call cannot be overturned, it is to say that if the umpire calls a ball fair (and thus alive), the play continues until review; not so the negative.

Because of the unlikelihood in proving the negative, the ball will likely be upheld as fair with 100% probability (even with only 50% probability of QOC); if not, then not. The no-call (e.g., fair instead of foul ball—all that keeps a play alive) is a preferred call because it is easier to call the whole thing off (e.g., call a foul ball retroactively) than to (1) overturn the call (foul to fair) and then (2) incorporate its consequences (e.g., place runners). A similar theory explains an official's tendency or incentive to call a close play, all else equal, in such a way that it is not reviewable.

The umpire's threshold for making a definitive call with replay available is therefore higher than it would be in the absence of replay. This is all work generally captured at the subconscious level.

All in all, umpires simply tend to be too good for this sort of analysis to go anywhere farther than the Books-Carleton approach of "any time managers see a challenge opportunity, they should take it." Opportunity cost is minimal, marginal benefit is conceivably significant and if the challenge is lost, the seventh inning beckons anyway.


Gil Imber said...

The first hit-by-pitch replay was confirmed ruling that it did not hit the batter by Barrett and Bailey.

Post a Comment