Handicapping Baseball Based On Home Umpires

Umpires can have a significant impact on a game if they make a bad call and the teams are separated by a couple of runs or less. We have already taken a look at how umpires affect totals betting in baseball, but today’s article will take a look at the myth that there are certain umpires that call games in favor of a home or a road team. If you are doing any baseball betting this summer, then you know that there are a lot of different factors that go into finding winners. We want to make sure that you are looking at the correct things and not making baseball handicapping mistakes or at least if you aren’t then you are sure that our baseball picks are the most research in the handicapping industry.

For this study we broke down home-plate umpires and the net units won or lost for the home team. We then broke down the results into the current season, and the previous two seasons combined, 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 show that the home teams are up +8.5 units currently, but -6.5 units the previous two years, putting the home team at +2 units over the two-and-a-half term when Jones is behind the plate.

The data we used covered almost 90% of the current umpires, so it should cover almost everyone in the big leagues. The results were pretty surprising as it showed that umpires are pretty fair with home teams having the same net unit gain and loss across the board.

The key here is that we are taking a look at a short term sample set, so there are going to be outliers in the study. However, we felt like the previous results did not correlate accurately to how this year’s teams were going to come out 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, meaning that there is no advantage to being a home or away team with a certain man behind the mask.

In this instance if we look at 100 umpires calling 100 games, then there aren’t any big time swings in home earnings vs away winnings. Any short term umpired trends in the baseball betting results are just aberrations. Let’s take a look at the results.

For example, the home team might have an 8-7 record for +1.2 units this season when Umpire Jones is behind the plate. One important note to point out is that we are only interested in net-units won/loss and not in the actual home team record per se. Net-units won or lost is ultimately how we determine profit on the moneyline, not wins and losses.

Our data set included the study of 57 umpires. Of these 57 umpires, 41 (72%) were within a range of +/- four units for the home team over the current season. 36 of 57 (64%) this year were within +/- three units. The remaining 16 umpires (28%) were outside of these parameters. Six umpires were classified as favoring the home team, a homer, and 10 umpires were classified as favoring the road team, a romer.

A homer here is defined as an umpire who is at least +4.1 units for the home team this year, while a roamer is an umpire who showed a minimum -4.1 units of profit for the home team (i.e. +4.1 units for the road team). We choose four units as the threshold since anything less than +4.1 units (or 60% for total analysis) could easily be impacted by a one- or two-game swing in a small sample size.

As we just noted, only six of 57 umpires (11%) were homers this year. This subset of umpires ranged from +4.7 units to +8.1 units. Of these six guys, five were either in the red for home teams over the previous two years or were no more than +3.5 units during this same earlier time period. This pretty much dispels any sort of theory that umpires will year in and year out show bias for the home team. That is, exactly one out of 57 randomly sampled umpires fall into both categories of being +4.1 units or higher for the home team this year and +3.5 units or higher for the home team the previous two years.

On the flip side there are 10 of 57 (18%) roamers thus far this season. Three of them were actually “homers” the past two years. So we are really only looking at seven of 57 (12%) umpires who were roamers in both time periods (this year and the previous two). So there is a slightly better case that certain umpires may in fact be road-team biased from year to year, but the results aren’t really conclusive.

Looking at trends from the last two years and how they apply to this year furthers our point. The majority of the umpires we examined (54%) were no more than +/- six units over the previous two seasons. In other words, the majority of the umpires were near the expected mean of +/- zero units.

Of the remaining 46%, nine were “homers” and 17 were “roamers.” In this case, since we are dealing with a larger sample size, we expounded our threshold and defined a homer as an umpire who is at least +6 units, while a roamer is an umpire who is at least -6 units for the home team. Of these nine homers from the past two years, five actually showed a zero or negative profit for home teams in the current season. Not one of the remaining umpires is more than +4 units this year. Again, this is a classic case of regression to the mean and totally discredits those who persist that certain umpires are biased towards the home team.

The same can be said for the 17 “roamers” (30%) from the past two years who were at least -6 units for the home team. Before we dissect these 17 umpires, it is interesting to note that at least on the surface there are more roamers than homers from the past two years, just as there are this year. So if anyone has a gripe about umpires, it might be that they are in fact more biased towards the road team. But we really are not buying this argument either.

This is because five of these 17 umpires showed a profit for home teams this year. In addition, 13 of these 17 umps (76%) either showed a profit for the home teams or are no more than -3 units for the home team this season. If there really was a conspiracy or a theme of particular umpires carrying a bias, we would see the same umpires show a consistent negative profit for the road team year in and year out, but it’s precisely the opposite trends that is unfolding here.

To sum up, there is no evidence to suggest that there is a contingent of umpires who have a tendency to favor the home or road team from one year to the next. For that matter, there isn’t a contingent of umpires who are better suited to cover an “Over” or “Under.”

Within a particular year, there may in fact be umpires who show a profit for home team bettors or road bettors. This is not surprising though, as teams much more often than umps will have a final say over the outcome of the game. As such, pure mathematics will suggest that out of 70 umpires, some will call more home wins than road wins, etc. Over time, however, these same umpires will be pulled the other way (regress to the mean of +/- zero units). So to put a lot of stock into which umpire is behind the home plate is generally speaking a fruitless exercise. In our assessment, that is.

This idea still may not sit right with certain handicappers and sports betting enthusiasts, but there are some exceedingly logical conclusions as to why these numbers turn up the way they do and the MLB odds shouldn’t be affected.