The month that was: September 2025 | Baseball Prospectus

Translated by José M. Hernández Lagunes

In this series we analyze the most important trends of the MLB in terms of racing annotation, pitching of position players and injuries, as well as the consequences of changes in the rules. This analysis is performed per month to identify trends per season.

The top of the classification is quite clear, and a glance at the bottom of the tables exposes a few remarkable waterfalls. Unfortunately, this exercise is not that impressive when half of the competitors are waiting for a score every evening. Yet thanks to the Rockies for maintaining the pace!

Racing Annotation

In September the teams scored 4.40 races per match, the month with the least amount of races since May. This is of course logical; The weather is cooler in September than in the summer months. (And yes, I know, pedantic, most of September is technically the summer. You know what I mean). Since the era of 30 teams started in 1998, only six septics breach (2010, 2012-14, 2022 and 2024) had fewer races. Of the months of this season, May only had a relatively lower racing score.

But not all those races were the same. Here is the race split for every nine entries.

The pitchers allow 3,201 races on 6,554 tickets in the first nine submissions of the September competitions. In extra innings they allow 91 races in 84 entries. And the position players – a subset of the totals of the first nine entries – were vaulted, making 20 races in 12 tickets possible.

Consequently, write to …

… It seems less impressive if you eliminate Zombie corridors and place players in position in the hill.

(Keep in mind that in earlier reports, until July of this year, I showed a racegrak for every 27 outs. Changing the denominer in Games makes a fair comparison between the two digits possible. Thanks to Ben Lindbergh for inspiring this review).

With regard to the races per match, September took place in the era of the 30 teams that really played baseball with real pitchers, as well as in the total races per game. The difference between the figures is a total of 0.15: 4.40 races per game, compared to 4.25 without zombie corridors or position players who are launching.

Here is the breakdown of the implementation of the universally designated seizure.

Position players who are launching

The teams that lose can only use a position player in the hill if they lose for eight or more races; The limit for 2023 was six. The teams that win can only use a position player as a pitcher in the ninth entrance, and only when they win for 10 or more races; There was no limit for use until 2022.

This caused a decrease in the number of position players in the past two years. But in 2025, despite the limitations, the teams used position players at an unprecedented speed, with 118 pitchers until the end of August, on the previous maximum of 103 in the first five months of the season, founded in 2022. However, the teams reduced the use of position players such as pitchers in September.

The 13 appearances of position -launchers in September were the least amount since 2021. But it was the fourth most in history, so it is not that they go out.

Those 13 performances by Werps were made by 13 players; There were no repeaters. Scott Kingeryfrom Sacramento, was filled by Los Angels on September 6 (12 hits, 2 balls per ball, a stroke, 8 races in 2 tickets) and Tyler HeinemanDue to Kansas City, the eighth entrance was removed after 10 races and 13 hits in an entrance and a third. So, although the position players were punished with an attacking line of .485/.500/.697 in the month, that figure is reduced to a respectable .226/.273/.323 without the two explosions. (This does not mean that position players are good pitchers).

Damage

Derek Rhoads and I have noticed that the most important trend of injuries of the 2025 season (more batter injuries, less jug injury) was reversed in July. In September the total injury also increased compared to 2024.

From 2 to 28 September (period in which the injured players were included in the injured list in September), the placements of the freezer increased by 25% compared to September 2024. However, this comparison causes two problems. Firstly, the templates could be expanded to 40 players in 2018 and 2019 in September. The injured players during the month were rarely included in the injured list, because the teams could replace them without worrying about the template size. (Fantasy players who try to convince the commissioner of their competition to enable them to replace their tolleter who broke their hand, knows well). Secondly, although the 2025 season ended on September 28, the last day of the 2021 season was 3 October. It was October 5 in 2022, October 1 in 2023 and 30 September last year. By adjusting the songs until the last day of each season, expressing the injuries per match and without paying attention to 2018 and 2019, we get the following:

Lave the bases

With the decoupling rule next to the launch clock implemented before the 2023 season, the stolen bases increased dramatically. But that also applies to the success rate in the theft of Basen, well above the balance point. This led people, including me, to wait even more stolen bases in the following seasons, with a lower risk aversion that reduced the success rate to the cost-benefit balance of around 75%.

They don’t listen.

As happened in June and August, both the number of stolen bases and the success rate in the theft of bases fell in September. 0.72 bases were stolen per party, the least amount in September since the change in the rules, and the success rate of 78.5% was also the lowest of the three years. These figures are still high, historical: the third largest number of robberies per game and the third highest success rate in September since 1998. But the impulse that meant the decoupling rule seems to be losing effect.

Playing time

The launch clock considerably reduced the duration of the competitions in 2023, but the duration of the games gradually increased in every month of the season. That’s why I was waiting for longer games in 2024. I was wrong. But this year I passed. Every month the competitions lasted (a little) more.

In September, the nine entries in which the local team hit the ninth entrance, on average 2:46, about five and a half minutes more than in 2024 (but two and a half minutes less than in 2023). The matches of nine tickets in which the local team did not reach the ninth entrance lasted 2:33, half a minute more than in 2024, but five minutes less than in 2023. There are many possible reasons for this, and the changes are not large, but the games certainly take more time. Do not be surprised if there are adjustments in the rules in the winter (I think they will be visiting the hill), especially if the challenges of the ABS are expected to expand the time of the games next year.

Thanks to Derek Rhoads for the data on injuries.