How Unlikely Was the Astros’ Combined No-Hitter?

On Monday night, the Astros celebrated Memorial Day by no-hitting the Rangers. Throwing to catcher Christian Vázquez, pitchers Tatsuya Imai, Steven Okert, and Alimber Santa combined for the 18th no-hitter in a franchise history that dates back to 1962. According to the great Sarah Langs, not only is that the most no-hitters over that period, but the second-place Dodgers are a full five no-nos behind with 13. Imai was making just his sixth major league start. Santa was making his major league debut. There must be something in the water in Houston.

I didn’t catch any of the game live. I saw a supercut that shows all 27 outs the Astros got. This is it. You don’t have to watch it to enjoy this article, and it’s seven minutes long, but I at least wanted to give you the chance to experience the game the way I experienced it.

Several things jumped out at me at the beginning of the video. It starts with an establishing shot of Imai. He’s toeing the rubber before he throws his first pitch, and his stats are overlaid on the screen. They are yucky. He’s 1-2 with an 8.31 ERA, a 1.79 WHIP, a 3:2 walk-to-strikeout ratio, and a 4.64 xFIP. With the Seibu Lions in NPB, Imai ran an ERA below 2.50 in each of the last four seasons. He was unhittable. But his first five-start stretch stateside was abysmal. He hit the IL with arm fatigue after three outings, got lit up in his first Triple-A rehab start, then got lit up again in his first start back with the big club. In the start after that one, on May 18, Imai put up a game score of 41. Somehow, it was his second-best mark of the season. He previously threw a curveball, splitter, and regular changeup, but he seems to have abandoned them entirely. “Command,” wrote The Athletic’s Chandler Rome, “has been somewhere between spotty and nonexistent.” All of this is to say that, to this point in his short MLB career, Imai has not looked like a guy with no-hit stuff.

Then the video gets going and we’re in for another shock. The first pitch we see Imai throw comes with runners on first and second! He had walked the first two batters of the game, at which point pitching coach Josh Miller leapt out for a mound visit and told Imai to consider shelving his four-seamer. How often does that happen in a no-hitter? Missing the strike zone with 10 of your first 12 pitches, and having your pitching coach tell you to just stop throwing your primary fastball? Imai listened, starting off Brandon Nimmo with two sinkers, but he missed even worse with those, so he went back to the four-seamer. The first pitch we see is a flat slider in the absolute center of the strike zone. It’s a meatball, and Nimmo rips it. Unfortunately for the Rangers, he crushes it right at the second baseman, precipitating a 4-6-3 double play.

The rest of the video has a similar feel. Imai strikes out only two Rangers over six innings. He induces a few popups, but it seems like every other batted ball is crushed up the middle, requiring a nifty play from Jeremy Peña, Nick Allen, or Brice Matthews, or smoked on a line into the outfield, requiring center fielder Jake Meyers to go spelunking into the gap with a great running catch. Okert, who pitched the seventh, and Santa, who closed things out, didn’t allow any hard-hit balls, but they struck out only a batter apiece, and Okert allowed a walk of his own.

My point in presenting the game this way is to demonstrate that to the naked eye, this seemed like a particularly unlikely no-hitter, and not just because Houston’s pitching staff has been the worst in baseball so far this year by ERA, FIP-, xFIP, and plenty of other metrics. Every no-hitter is unlikely, of course. Conventional wisdom says that each no-hitter requires one great defensive play. But plenty of things can make a no-hitter more likely to occur. No-hitters tend to feature lots of strikeouts, because that minimizes the amount of havoc the BABIP gods can wreak. They tend to feature a low number of walks, because pitching with runners on base is harder and leads to surrendering more hits (and because pitchers who are walking a ton of batters often don’t have their best stuff). And I would imagine that they tend to feature few hard-hit balls because hard-hit balls tend to fall in for hits. The Astros achieved none of this during their no-hitter, so I decided to go through Statcast data to see just how unlikely this one really was.

I should start with something that’s more of an oddity than anything else. Imai, Okert, and Santa are all fastball-slider guys. (Santa throws both a regular slider and a sweeper.) Aside from four Imai sinkers, every pitch the Rangers saw was either a four-seamer or a slider. The Astros didn’t throw a single curveball, cutter, or offspeed pitch all night. Going all the way back to the beginning of the pitch-tracking era in 2008, that’s only happened 34 other times, or just under twice a season. It doesn’t happen much because mixing things up, throwing different pitches with different velocities and movement profiles, keeps hitters guessing and messes with their timing. It is helpful. Not doing so is extremely unusual.

Alright, on to the numbers. Since 2015, we’ve seen 43 no-hitters. I pulled all the stats I could think of, then looked at where this Astros pitching performance stacked up among that cohort. Here’s a table, and in honor of Statcast, we’ll use percentiles rather than plain old ranks.

Yeah, I’m going to go ahead and deem this an extremely unlikely no-hitter! The highest percentile on this table is barrel rate, at 38! By no-hitter standards, the Astros got lit up. They ranked toward the bottom in everything. They were hit harder, they racked up fewer whiffs, and they had nearly the highest expected batting average in the group. Teams that throw no-hitters nearly always strike out more or walk fewer batters; and they always do at least one of the two. The only other no-hitter with a negative K-BB in our sample came on June 24, 2021, when four Cubs combined to walk eight Dodgers and strike out only one. According to Stathead, of the 194 no-hitters in the expansion era, this is just the 16th ever to feature a negative walk-to-strikeout ratio and the fifth this century.

This seems like a good spot for the classic elementary school tell-them-what-you-just-told-them conclusion so we can reiterate all the ways this game was unlikely to end up as a no-hitter. The Astros have the worst pitching staff in baseball, at least so far. Imai came into the game with a disastrous 8.31 ERA in his first five MLB starts, and spent a month during that stretch on the IL with arm fatigue. He’d just abandoned a bunch of pitches, and he started out the game completely unable to find the zone. He allowed a 50% hard-hit rate and walked twice as many batters as he struck out. Santa was making his first major league appearance ever. The three pitchers threw either a four-seamer or a slider on nearly every pitch. They did only a decent job of avoiding hard contact, and a terrible job by no-hitter standards. They didn’t whiff anybody. They walked more batters than they struck out. And then they got drenched in Gatorade anyway. This game is stupid and I love it.