Once you start peeling the layers of all the ejection data dating back to 2008, there is a bigger story to be told which many analysts have looked over. While ejections have increased since the start of instant replays, I believe we will see a strong decline in ejections for two main reasons.
First, the number of ejections made at first base declined from 15 percent to 9 percent. Ejections are less likely to occur at first base due to the introduction of instant replays, since replays decrease the chance of umpires making an incorrect call. So why are were there more ejections made last season? There are two explanations: an unprecedented increase in pitchers being ejected and an increase in ejections due to replays. Pitchers got ejected more last season than in recent history because of intentional hit by pitches. Because this data has no relevance to instant replays, then pitcher ejection rates will decline in future years which means that ejections will be lower in a world of instant replays than without them.
Second, many ejections occurred from instant replays themselves. There were some replays that were blatantly incorrect. Even people who take second looks can make the wrong decision. Because 2014 was the first year instant replays were introduced, we will see a decline in ejections related to instant replay due to a steep learning curve. Those who look at instant replays from abroad will make better decisions, while coaches and players will get more assimilated with the new rule.
Here are some additional fun facts:
Observation 1: A player is about 25 percent more likely to be ejected if they are loosing the game.
Observation 2: A majority of ejections (52 percent) are from balls and strikes. The introduction of replay review decreased safe/out ejections by 19 percent. However, ejections from replay review are about 12 percent of all ejections.
Observation 3: Ejections increase by 20 percent during the second half of the season.
Observation 4: Ejections are most likely to occur in the 7th and 8th inning, 17 and 16 percent respectively.
Observation 5: Out of all ejections, mangers get thrown out 48 percent of the time, pitchers and catchers at 11 and 5 percent respectively. However, pitchers were ejected at a record high last season, which can be attributed to more hit by pitches.
Observation 6: When evaluating whether an umpire makes the correct call on a play that ends up leading to an ejection, umpires are correct 53 percent of the time, incorrect 21 percent of the time while the remaining 26 percent is indeterminable.
Observation 7: Looking at data since 2008, there was not enough evidence to determine a relationship between a team’s win percentage and the number of player ejections (p value of .48).