Instant Replay

Before 2014, instant replays in baseball were restricted to disputed home runs, fair vs. foul, fan interference, and wall border calls. This season, the scope of replay expanded greatly with the introduction of a challenge system similar to the one in the NFL. Now, it’s possible for managers to challenge practically everything short of ball-and-strike calls, and they have taken advantage.

Between 2008 and 2013, the six years of the original replay system, only 384 replays were used and only 129 plays were overturned according to data collected by Baseball Info Solutions. With still a month to go this season, 1,056 replays have been used and 495 plays overturned. We are on pace for about 600 corrected calls that would previously have been missed.

Overall, replays are overturning calls at a higher rate than the previous system, but not all types of challenges have been equally successful.

More than 80 percent all of replays have been on either disputed tags or force outs, and they have collectively been close to a 50/50 proposition. Replay has overturned 417 of those 861 calls (48 percent).

Other types of replays have been far less common, but, even with limited sample sizes, a pattern emerges. For example, 21 of the 26 replays on trap or catch plays have been overturned (81 percent). In contrast, only 18 of the 67 boundary call situations—which include potential home runs, potential ground-rule doubles and fan interference plays—were overturned, only 27 percent.

The Instant Replay section of the Bill James Handbook 2015 will be expanded from last year's edition to capture the increase in scope of replays. The book is available for pre-order here.