Predicting MLB Extra-Inning Games Using Machine Learning (2022)

I am going to start this article with data supporting why, under no circumstances, you should ever bet an MLB game to go to extra innings before the game begins. Then, I am going to take you down the wrath of statistics and machine learning as we become the most knowledgeable extra-inning bettors in the market. By the end of this article, my hope is that you, as analytical gamblers, will be equipped with extra-inning knowledge second to none, and your sons and daughters will live to hear of the day when that knowledge began.

Exploratory Analysis

Let's get the bad out of the way. Since 2017, extra-inning games occur about once every 11.96 games (8.36%). Each year is different, but 2022 is hovering a little above the average at once every 11.73 games (8.52%). With that in mind, without any vegas juice, an implied extra innings percentage of 8.36% should yield an average bet of +1096. However, as I am writing this article on the eve of August 5th, the average price for the 14 games to go to extra innings tomorrow is a measly +717 which implies odds of 12.24%. The vig is something that is a part of every bet as it is what keeps Vegas in business. Nonetheless, with DraftKings assuming an implied odds of a game going to extra innings 46% higher than what we have seen over the last five years, there should more analysis before hitting Place Bet.