A year has passed for the Insurgents. In fact, those of us who follow these things closely know that 2023 and 2024 were both considered years of separation, and then we determined back in March that 2025 would be the year of separation. While major league pitchers are hitting 3.3 percent of their pitches in 2025, the highest level since the pitching tracking era began in 2008, it’s only up 0.21 percentage points from 2024. Each team’s scoring average differs by less than one goal every three games. While the numbers are still rising, the big increases occurred in 2023 and 2024, with growth slowing this year.
This diagram formalizes it. This is not the year of division. But now let me add another line to this graph. That’s the regular season. We’re in the thick of the playoffs, so let’s factor that in as well. If you saw the first picture and wondered why I left all the white space at the top, now you know.
This is more like this. In October 2025, a separator explosion occurred. The red line will always fluctuate more than the blue line because the postseason sample size is so small, but even so, the postseason split rate is still a whopping 6.6%. It’s not just the highest level we’ve ever seen. That’s twice as many as any regular season or playoff game in the past 23 years. Maybe 2025 is the year the kickers change, but October 2025 will definitely be the month of the splitter. The playoffs aren’t over yet, and we’ve already seen more Splitters this October than in the 2023 and 2024 playoffs combined.
As for why it is Separation Month, there is no big answer. Instead, we get a lot of little answers. The first is the teams that make the playoffs. Overall, they were very happy about their breakup. Eight of the 12 playoff teams rank in the top half of the league in splitter usage, and four of them rank in the top 10. They used the point shooter a total of 4% of the time, compared to 3.1% for teams that didn’t make the playoffs. The Blue Jays lead the league in run rate at 9.3 percent, the Dodgers are third at 7.1 percent, and their depth means we’ll likely push that 6.6 percent number even higher during the World Series. What’s more, 9 of the 12 teams that made the playoffs improved their scoring rate during the postseason. The Blue Jays have a winning percentage of 16% in the playoffs. Nearly one in six pitches thrown by the Blue Jays this October was a split ball!
The same story applies to individual players. So far, 38 players who pitched in the regular season have pitched in the postseason, but they’ve done so in far greater numbers. During the regular season, these 38 pitchers combined for an 18.3 percent pitch rate for their respective teams. During the postseason, these pitchers hit 36.2 percent of their pitches. If you throw a splitter, your workload actually doubles in the playoffs! We had Kevin Gausman pitching on his side day and Bryce Miller pitching on short rest. We have Roki Sasaki as the shutdown closer and Eduard Bazardo pitching seemingly every game.
Additionally, it appears that at least some of these 38 players were drafted for throwing splitters. I say that because, as a group, they are throwing the split ball more often than they were during the regular season. Once you prorate the number of shots they take based on their regular season distribution rates, you’d expect these players to have a 16.7 percent distribution rate in the postseason. Instead, their diversion rate combined was 18.3%. The Tigers had the second-highest increase in points allowed and were at the top of the leaderboard. Rafael Montero, Kyle Finnegan, Casey Mize and Troy Melton all saw increases of at least 17 percentage points. The Blue Jays and Dodgers are close behind, with Sasaki, Jeff Hoffman, Trey Jesavich, Gausman and Shohei Ohtani also rounding out the top 10.
All of this makes sense once you look at the offense in the playoffs. Yankees and Guardians hitters saw a walkout 4.2 percent of the time during the regular season, tied for the highest rate in baseball. Teams clearly thought they could attack them this way during the regular season, so the Tigers certainly upped their scoring percentage against Cleveland in the playoffs. The Yankees have a .251 wOBA against splitting balls and a .342 wOBA against all other pitching. The 91-point margin was the fourth-largest in baseball. The Mariners are seventh in the differential, and then both the Yankees and Mariners take on the Blue Jays, the league’s most divisive team. No wonder Toronto is pushing the diversion rate even higher! The Brewers’ 69-point deficit was ninth in the league and they had to face a Dodgers pitching staff that had a 7.1 percent regular-season strike rate, the third-worst in baseball.
As for the World Series, we’re definitely going to see a lot of splitters due to pitching issues. The Blue Jays and Dodgers were both hitting exceptionally well this season, but their performance fell off significantly in October. The Blue Jays are hitting .345 against the Splitters, allowing 2.3 runs per 100 pitches. Both scores are among the best in baseball. Toronto is also the only team with a better wOBA against splitters than non-splitters. The Dodgers’ .298 wOBA against the Divisors ranks fifth in baseball and their 1.2 runs per 100 points ranks fourth. However, in the playoffs, both teams had negative runs on the field and a combined wOBA of 0.170. The division is likely to continue.
