Baseball Betting Umpires

It seems like umpires take a lot of heat from fans and bettors both.  A bad call can sometimes have a huge impact on the game, so if it’s a tight game and old blue blows one behind the plate then he’s going to get a few choice words screamed his way.  Most people think that these bad calls are random events that come out of thin air, but plenty of baseball handicappers take the man behind the plate into consideration before making their baseball picks.  If you are doing so, then we think you should also read our baseball handicapping mistakes article.

If the umpire has a small strike zone then one would think that he would be hitter-friendly and one would assume he would have a tendency to call games that go over the posted total.  However, the reverse would also be true, where a big strike zone would favor the pitcher and have a tendency to see games go under the total posted for the MLB odds.

Since we know that a lot of services in the industry were big on this trend, we decided to do a little research of our own.  We took a look at home-plate umpires and their over/under records and then broke down these stats into the current season, and the previous two seasons, obviously using the previous two seasons as a bench mark for how playing those baseball trends would factor into betting on the current season and vice-versa.

For example; home-plate Umpire Jones might be 10-8 (o/u) this year and 35-39 (o/u) combined the past two seasons.  This would put Jones at 45-47 (o/u) the past two-and-a-half seasons.

The data we used covered almost 90% of the current umpires, so it should be a fairly accurate relation even though it doesn’t cover every single event.  The results were pretty surprising.  It showed that umpires are pretty unbiased and went over and under the total very close to 50% of the time.

The key here is that in the short term phase that we used, there are going to be guys who gravitate towards the poles, and that was the case in our study.  However, we didn’t feel like any previous results correlated accurately to how this year’s teams were going to perform with that man behind the plate.  As time progresses we feel like the outliers who were away from the mean early, will eventually regress towards it.

In this instance if we look at 100 umpires calling 100 games, then there aren’t any guys who see more than 60% over or under. We think this study shows that short term umpire trends are more happenstance than anything else.

Let us go over the baseball betting results of the study and then proceed to offer some possible explanations. The results will be broken down based on the following variables: O/U for the time periods; year to date vs. the last two seasons combined.

Over/Under Results

Surprisingly, even in the short term (this year only) most umpires gravitated towards a 50/50 (o/u) split.  The results showed that 28 of the 57 (49%) umpires were between 40% and 60% (o/u).  We think that for an umpire to be considered biased one way or the other there had to be at least a 60 percent or better pattern for either the over or the under.  This does mean though that the remaining 29 umpires (51%) were above the 60-percent threshold.  This sounds like we could have a promising trend until you examine the subset more closely.

Of these 29 umpires, 13 of the umpires gravitated towards the under, but seven (54%) of the 13 were at least 51% over during the previous two seasons.  Of the remaining six, only three were at more than 53% under in the latter periods, which significantly cuts down on the strength of the argument.  This is because we basically see most under umpires this year were over umpires the last two years. The same concept holds true when we examine umpires who in the current year have gravitated towards the over.

There are 16 umpires who have called games that had the over cash in at more than 60%.  Of these 16, nine (56%) were under umpires the last two years.  If you take it one step further then 14 of these 16 umpires (87.5%) were either under or less than 55% over during the prior two seasons.  This means that only two of 16 were over 60% over in both periods.

Now let’s take a look at the first two years to get a larger sample of data, and then compare that to how we would have done if we bet those plays on the current season.

The key here is that only six out of 57 umpires (11%) were 60% or more over in the previous two seasons combined.  Also, there were only four of 57 umpires (7%) that were under at more than a 60% or more rate during this same period. This implies that 47 of 57 umpires (82%) were between 41% and 59% either over or under.

However, it would be profitable if we as gamblers could hit at a 55% rate over a two year period, so we thought we would drop the qualifications down a little bit to see if we could enlarge our group.  Even with this number in place our results still show a general regression to the mean. Specifically, there were 20 of 50 umpires (35%) who were a minimum 55% under for the past two seasons combined.  But of these 20 there are only 7 that are at least 51% under in the current year.

Of the remaining umpires, three of seven are 56% or less under for the current year. In sum, 16 of the 20 umpires who were at least 55% under from the past two years were either over this year (13 umpires) or less than 56% under (three umpires).  Again, we see a powerful regression to the mean taking place here.

The last observation with our totals analysis is that 13 out of 57 umpires (23%) were at least 55% over from the past two years.  However, of these 13 umpires, seven (54%) flip-flopped and were at least 51% under in the current season.  Two of the remaining six umpires have had lower over ratios in the current season than they had in the last two combined.  So basically, nine of 13 umpires (69%) who were over in the last two seasons have regressed back towards the mean in the current year.

If you liked this article then read our full article on umpire betting on home/away teams.