If They Don't Score, They Can't Win
The Astros Have Won 10 Games in Row, and Allowed Only 11 Runs in Those Games. An Anatomy of Run Prevention in the Win Streak
It’s 10 games now.
The Astros won two games yesterday in Minnesota, defeating the Twins 11-3 in the resumption of the game suspended on Wednesday night and then winning the nightcap 5-0. That pushed the Astros winning streak to 10 games.
And the Astros are winning for a very simple reason: they are not letting their opponent score any runs. Opponents have scored only eleven runs against the Astros over the last ten games. That’s just about one run per game. The win in the second game yesterday was one of five in the streak where the Astros shut out their opponent. The three runs allowed in the suspended game are actually the highest number the pitching staff has allowed during this streak.
And if your opponent can’t score, they can’t win. While the Astros bats showed some signs of waking up in Minnesota, the team has scored 4.9 runs per game across the win streak. That’s a good number, but still below the 5.3 runs per game the team scored throughout the 2021 season. The team is winning right now because it’s shutting down the opposition.
The numbers for the pitching staff are quite impressive. They have thrown 90 innings in the 10 games, allowing 11 runs (9 earned), 57 hits, and only 20 walks. They have struck out 82 batters, and—most impressively—allowed only 2 home runs to the 337 batters they have faced.
The chart below shows the stats across the win streak, and you can see how these raw numbers above translate to rate stats that are outstanding. Their ERA is less than a run per 9 innings. The WHIP number shows they allow less than a baserunner per inning, in large part because they are walking so few batters. And the slash line for opponents is .181/.234/.232. Astro pitchers have been turning major league hitters into the equivalent of an overmatched minor leaguer in an emergency call-up to the bigs. In short, these numbers are quite impressive.
The credit should be shared equally between the starting staff and the bullpen. The starters have allowed an ERA of 0.92, and the bullpen has done a smidge better at 0.86. The WHIP numbers are similar—with the slightest of edges to the bullpen (0.83 to 0.87). The starters do get the slight edge in walks allowed—they are allowing only 1.99 per nine innings compared to 2.01 for the bullpen). In short, the Astros are shutting down opponents at the start, in the middle, and at the end of games.
Great Defense, Too.
It’s been a total team effort to shut down opponent bats.
And that includes contributions from the rest of the defense. Astros opponents have a batting average on balls in play of .238 during the win streak, well below the league average of .282 for the entire 2022 season. The way to interpret that stat is that Astro defenders are turning a higher percentage of balls hit by opposing hitters into out than the average major league team.
You will note that the FIP for Astro pitchers during this win streak is 2.46, but their actual ERA is 0.90. Turning more balls into outs keeps runs off of the board, and the discrepancy between the number of runs the Astros “should” give up and the number they actually are is explained in part by the excellent defense that the Astros are playing.
Across the 2022 season, the Astros lead the majors in two major defensive stats—Defensive Runs Saved and Outs Above Average. They are ranked 2nd in Fielding Runs Above Average, 3rd in Defensive Efficiency, and 7th in Ultimate Zone Rating. Defensive stats are notoriously finicky, but the consistency of the Astros at the top of these different measures shows how that none of their ranks in their individual measures is a fluke. This team is good at taking hits away from their opponents. And it is leading to fewer runs on the board against them.
The win streak will not last forever, but there is little reason to think that the Astros will not keeping winning a large share of ball games. They play a series of teams outside of playoff position over the next month. Over their next 31 games, the best teams they will play are the Cleveland Guardians (May 23-25) and the Chicago White Sox (June 17-19), both of whom are exactly .500 so far this season.
As it has been on so many days since the Golden Age of Astros baseball began in 2017, it’s a good day to be an Astros fan. And it look like we’ll have more of those days in the near future.