While much of America was focused on the second presidential debate, the Blue Jays and Rangers were battling through a back-and-forth ballgame that ended in a walk-off error in the 10th inning. By one measure, it was the most exciting game of the MLB playoffs so far.

I came to that conclusion by calculating a baseball version of the Excitement Index, a metric originally developed for basketball. The idea is simple: We can estimate how likely each team is to win a game at any given moment by looking at how teams have fared in similar situations historically. If a team is at home and trailing 0-1 at the end of the first inning, they are expected to win the game 39.1 percent of the time. Later on in the game, if the same team goes up 3-2 in the bottom of the fourth inning, their win probability jumps to 65.6 percent.

Exciting games tend to feature lots of movement in win probability. Big events like lead changes or bases-loaded strikeouts cause win probability to volley back and forth as the favored team changes. To measure the overall excitement of a game, I simply took the total of the changes in win probability over the course of the matchup. And by that standard, the Blue Jays-Rangers game last night was the most exciting of the playoffs so far :

GAME DATE HOME TEAM VS. EXCITEMENT INDEX 10/9 Toronto Blue Jays Texas Rangers 4.05 10/9 Washington Nationals Los Angeles Dodgers 3.19 10/8 Chicago Cubs San Francisco Giants 1.6 10/7 Washington Nationals Los Angeles Dodgers 2.95 10/7 Texas Rangers Toronto Blue Jays 2.57 10/7 Chicago Cubs San Francisco Giants 2.15 10/7 Cleveland Indians Boston Red Sox 1.13 10/6 Cleveland Indians Boston Red Sox 2.79 10/6 Texas Rangers Toronto Blue Jays 1.12 10/5 New York Mets San Francisco Giants 2.84 10/4 Toronto Blue Jays Baltimore Orioles 3.7 How exciting have the playoffs been so far? Source: Fangraphs

The matchup last night was spiced up by three lead changes, one of the best young pitchers in the game in Aaron Sanchez, and a simmering rivalry between the clubs. It also featured the third-most-impactful (by win probability added) single play of this year’s playoffs — the sixth-inning Mitch Moreland double for Texas that flipped a tenuous 5-4 Blue Jays lead into a one-run deficit. That shifted Toronto’s win expectancy from 67.3 percent to 35.3 percent.

But as with many contests, the most subjectively exciting play was the one that ended the game. In this case, that was a Russell Martin groundout that should have resulted in a double play. Instead, due to some sloppy defensive play, Rangers second baseman Rougned Odor ended up skipping a throw to first base, which allowed Josh Donaldson to bolt in from third as the winning run. For two teams with a contentious history, Sunday’s finish felt serendipitous.

For now, the Jays and Rangers are parting ways. Toronto advances to the ALCS and now boasts a 23 percent chance of winning the World Series according to our projections, though they still face a tough matchup against either the Red Sox or the Indians. Meanwhile, Texas goes home after a fascinating and miraculous season. With any luck, these two clubs will find their way back to each other next October, when they can continue their tradition of exciting postseason games.