MLB Totals Simplified

The @PinnacleSports Twitter account highlighted a 2016 article on totals betting in Baseball, with the following quote highlighted:

"At most bookmakers it is effectively impossible to beat the Over because unsophisticated bettors tend to go Over not realizing that the numbers don’t add up the natural way."

By extension, if the market is so efficient that you can't win on Overs, then you can't win on Unders either, but it's not that clear cut. The article itself includes this comment:

Even at Pinnacle we can’t be sure that we have the best of it, especially when the person betting is sharp, so often we have to move the line and offer what we think is likely to be value. While the under is more likely to offer you value on a game where you don’t particularly like your side – especially if you’re playing at another bookmaker than Pinnacle – the over is where you can have vastly the best of it in the right spot. It’s never a sure thing that a pitcher will get it done.

As is often the case, the article complicates what is really quite a simple problem to solve. Let the market do its stuff, and take advantage of its inefficiencies.

I apply a similar strategy in baseball to that for the the NBA. When the total is (relatively) high, my expectation is that the public will be deterred from backing Overs, and Overs can thus offer value. 

Similarly, when the total is (relatively) low, the Under doesn't appeal to the unsophisticated public, and this selection can offer value. Remember:

Most punters lose. They are ill-informed, intrinsically lazy, psychologically flawed, impulsive, ill-disciplined, incapable of appreciating the importance of affect to the decision making process and prone to imitative and repetitive behaviour.

MLB has two conferences, and two sets of rules, with significant differences which need to be taken into account, and games hosted by the Colorado Rockies always have a higher total, something else that needs to be treated as an exception. 

The average total of runs per game over the past five seasons (including the current 2019 season) is 8.3 in the National League, 8.6 in the American League, and 11.0 for games in Denver.

The Totals markets are, at first sight, remarkably accurate.

For the National League, Overs and Unders are split as shown above, and the American League is close to 50/50 at 50.8% in favour of Unders.

First sight can be misleading however. 

By adding a few conditions to my Totals bets, for example with Overs, I want the favourite to be the away team, (since that increases the chances of both teams batting all nine innings and 54 at-bats is much more favourable than 51 when you're wanting runs) it's not hard to see where the market weaknesses are. 

I reverse the rules for the Unders, and as you can see below, this is also a profitable strategy.

Results for the latest five seasons:

It's a simple, and extremely time effective, strategy. There may be sophisticated models out there, requiring a lot more effort, and requiring huge databases for evaluating pitchers and batting line-ups, but how many of them can match or exceed the double digit ROI percentage on Overs since 2015? 

Likely not many. Simple is often best - the KISS principle.