The first major signing of 2026 broke on New Year’s Day as the Houston Astros landed Japanese ace Tatsuya Imai on a three-year contract. Imai, who gets an opt-out every year of the deal, will be guaranteed $18M per season with performance incentives totaling $3M per season, bringing his total possible earnings up to $63M. The entire baseball industry was virtually unanimous in expecting Imai to secure a bigger payday, as projections from The Athletic and Fangraphs had him signing for 9 figures. It was also surprising that he went to Houston since there was much more buzz surrounding other teams with incomplete rotations, like the Orioles, Mets, and Cubs, as potential suitors.
This didn’t unfold the way many anticipated, but it’s very easy to talk yourself into Houston as an excellent fit for Imai. Early in the offseason, the public was quite bullish on him because his fastball specs drew some Joe Ryan comparisons. Those are not to be thrown around lightly because Ryan has one of the best four-seamers in the game – despite unimpressive velocity at 93-94 mph, it has above-average vertical movement relative to his lower arm slot, creating a ‘rise’ effect that leads to a lot of missed bats. However, the NPB baseball is different than MLB’s, and pitchers who have made the jump from Japan to the big leagues have seen changes to their fastball shapes as a result.
Marquee Sports Network’s Lance Brozdowski’s current estimate for Imai’s fastball shape in MLB is 12.5 inches of both induced vertical and arm-side break, and proprietary Japanese data sources have his arm angle around 20°. See below for the complete list of pitchers who had between 12 and 13 inches of iVB, between 11 and 14 inches of arm-side movement, and an arm angle between 15° and 25° on their fastballs:
The fact that Imai will be throwing a slightly different baseball in 2026 means that his four-seamer won’t quite land in Joe Ryan territory, but a Luis Castillo-esque fastball wouldn’t be a bad thing at all, especially considering that Imai has an advanced five-pitch mix. As well, some sources indicate his heater maxed out at 99 this past year, which theoretically increases its upside. Even if it isn’t as vertically oriented as the likes of Ryan’s, or the “Invisiball” of Bryan Woo, it will almost certainly be one of the flatter offerings in the league. A vertical approach angle of less than 4.5° seems like a lock.
Why is this important? For years, the Astros have loved flat fastballs. Imai, Cristian Javier, Hunter Brown, and many others on Houston’s staff all have that one thing in common: Flat four-seamers that play up in the zone with plus vertical movement given arm angle. Take a look at some more of their notable pitchers who fit this description, with Ryan also highlighted for reference. Reminder that just a few weeks ago, they scooped Mike Burrows from Pittsburgh as a cost-effective option for the back of the rotation with team control. He’s a part of this group, too.
Notable Houston Astros (and Joe Ryan) with flat fastballs, 2025
Imai will fit right in. There’s no denying that if his first MLB season is a success, he’ll opt out and render this contract a 1-year deal. It’s also true that Houston made some cuts to an already-thin farm system to acquire Burrows. However, if they’re not going to spend hundreds of millions every free agency, these are the types of moves it takes to stay competitive, even after their long-term reign over the AL West came to a close in 2025. If Cristian Javier can at least partially regain his pre-elbow-surgery form, then between himself, Hunter Brown at the top, and Imai and Burrows adding depth, this looks like a playoff-calibre rotation. The sun finally appears to be setting on their empire, but they’re not going down quietly.
The franchise also has a solid track record of optimizing arsenals. Hunter Brown added a sinker and became one of the AL’s best starters. Ronel Blanco broadened his horizons and stopped being a fastball/slider guy 90% of the time before the 2024 season and promptly broke out in a big way. Imai has a unique “wrong-way” slider with arm-side movement (those used to be called screwballs back in the day – think Trey Yesavage’s slider except from a low 3/4 slot), a splitter, a changeup, and a curveball he used sparingly. The slider got the most chase and miss of his repertoire, and with multiple secondaries that move in all sorts of different directions, there are plenty of ways his mix can be adjusted to position him for success in 2026. Recent history suggests he’s in the right place.
The Astros were not an apparent favorite to land Imai, but in more ways than one, he is exactly the kind of pitcher they covet. For all the mystery and intrigue surrounding his fastball shape and whether it will hold up at the highest level, he throws hard and owns a diverse arsenal, which leaves him with a wide range of potential pathways to becoming an effective big league pitcher. They may have missed the playoffs for the first time in a decade, narrowly getting eliminated in the season’s final weekend, but they’ve made a couple of quality additions to their rotation and figure to contend once again in 2026. Imai bet on himself in free agency and just might have wound up in an ideal environment in terms of his chances of getting a heftier contract next winter.
