So far this year, the Braves have played in 28 1 run games. After going 9-9 in the first 18 of them, they proceeded to lose the next 10 in a row, and are now 9-19. In baseball, everything to do with winning happens at somewhere in the ballpark of a 50 percent probability, so losing ten in a row of anything is pretty unlikely, as long as you’re at least mediocre. But unlikely certainly doesn’t mean impossible: unlikely stuff happens all the time, given how many teams are playing and given how every team’s win is another team’s loss. Still, though, it’s hard to put things like this in context unless you understand the context. It’s the context that I intend to lay out here. Application to the Braves’ situation can then be done in a contextually appropriate fashion.

How Common Are 1 Run Games?

How many one run games does a team expect to have in a season? This is a pretty easy question. From 2000-2024 (excluding 2020) teams average 46 one-run games per year. This value has been coming down over time, since more powerful offenses create a greater variance in run differentials: from 1961-1975, it was 52 games a year. Overall, it looks like this:

There is, however, one factor that shifts the expected number of one-run games per year. Mediocre teams play more one-run games than either great team or horrible teams, both of whom play in more blowouts. The effect is pretty small, though. Even with this amount of data, the number of one-run games a team plays in a year doesn’t have a great explanation beyond the overall run environment.

The effect really shows up when you look at the level of individual games. If you look at a game and the absolute value of the difference between the two team’s winning percentage (at the end of the year, not at the particular time of the game) you do see that bigger mismatches have somewhat lower probabilities of a one run game, but the effect isn’t huge:

Pay no attention to the big divergences on the right hand side of this graph (which, for those of you care, is a logit regression on about 135,000 games from 1961-2024.) There are just very few games in which the mismatches are this large. In any case, the effect is fairly small.

So, through 65 games, 28 is certainly well above average, but not amazingly so. In 2021 the Amazin’ Mets played 66 one run games. The 162 game record (set in a low run era in a low run ballpark) is 75 for the 1971 Houston Astros. The Braves are currently on pace for 70, though. I suspect this is just one of those early season anomalies, though, and I would predict no more than 60 or so. Above average, but not historically so.

How Often Do Teams Win One Run Games?

It should come as no surprise that the probability of winning a game with a one run difference is exactly 50 percent. Every single time.

But which of the two teams will win? It should come as no surprise that the better teams win these games. What may be a little surprising is how much it explains. From 1961-2024 (dropping 2020) there were 40,110 one run games. I selected the road team and used the difference between their winning percentage (for the year) to predict the winner. The results were quite good:

Note that winning percentage when the power difference is 0 is somewhat below 50 percent — that’s just the home field advantage. As before, ignore the seemingly bad fits on both the right and left of this diagram — there are just very few games at those levels of power divergence and the actual has a large random component.

Takeaways

You can’t really apply this model to the Braves’ current situation directly because you don’t know their final winning percentage nor that of their opponents. But applying their current winning percentage and that of their opponents as a proxy, you can get some idea of the likelihoods here.

Here are the stylized results (calculated as of games through 6/10):

The Braves have a 28-38 record. That’s a 0.424 winning percentage. Using this and every other team’s current winning percentage, the Braves should have played around 17 one run games instead of the 28 they have played. This pretty unlikely. Using a simple simulation, I find that the chances the Braves would have played 28 or more one run game at this point is only .00406, 406 out of 100,000 .. a little under 1/2 of one percent. But since 1966, the Braves have played lots of 66 game sequences… they play almost 100 every year so they’ve played about 60,000 such sequences, so they should have had quite a few by this point.

I also calculate that in the 28 1 run games they’ve played, they should have won about 14, instead of the 9 they have won. This isn’t nearly that unusual. Again, simulating 100,000 such sequences, I find that the Braves would be expected to win 9 or less 3.7% of the time. That said, the probability that they would have lost the last ten in a row is really unlikely. Repeating the simulation just for the last ten 1 run games, the probability of winning none of them is well under 0.2%, 165 out of 10000. Given that there are far fewer sequences of 10 consecutive 1 run games, this really does show that Raisel Iglesias has sucked, if you didn’t already know.