The Launch Angle

Remember my post from last week? About the Astros’ pitching staff, I stated, “There are seemingly more names than roles readily available, so you can see where adding another pitcher isn’t high on the priority list, other than if a clear upgrade is possibly attainable. If there is a desire to add another pitcher, it is likely on the back burner for now.“

Needless to say, that small paragraph didn’t age well, at least entirely.

I guess watching the 2025 pitching staff evaporate so quickly left a lasting impression on Dana Brown and the front office, as they decided to bolster the pitching depth chart even further, trading for right-hander Kai-Wei Teng from the Giants and signing left-hander Tom Cosgrove. It is debatable whether the pair represents a clear upgrade, but more depth is never a bad thing. Again, you can never have enough pitching.

Let’s talk about Teng for a minute, because he is intriguing in his own right. The 26-year-old from Taiwan, originally from the Twins’ farm system, has been with the Giants’ organization for the majority of his career since 2019. He struck out not quite a third of opposing batters in Triple-A last season (89 in 57 innings!), with a 3.63 ERA and 2.95 FIP. While a generally fine ERA and an even better FIP are always nice to read, I am more intrigued by the strikeout numbers.

Strikeout Rate By Season (AAA)

• 2025: 37.1%
• 2024: 17.0%
• 2023: 27.6%

His major league performance in the past two years isn’t particularly noteworthy, but we also can’t draw too many firm conclusions based on only 35 innings. So, that 7.30 career ERA, you can simply ignore it. But he did strike out 39 in 29 2/3 innings last season, so we can see where this guy caught the Astros’ attention. The fact that he has experience as both a starter and a reliever likely played a role, too. I have always liked some versatility on a pitching staff, and Teng looks like he can provide that. Perhaps he can be this team’s 2026 version of Brad Peacock?

I am curious to see what the Astros do with Teng’s pitch arsenal. He offers a six-pitch mix, with a sweeper, four-seam, curveball, slider, sinker, and changeup all being used in some fashion in the past two seasons. His sweeper, in particular, was his most-used pitch and his best in 2025, limiting opposing hitters to a .255 slugging percentage. I’d be surprised if the team’s pitching lab doesn’t keep that as a focal point in his arsenal.

One of the more interesting things to watch is what the Astros do with Teng’s fastball, whether they want him to keep the four-seam or implement more of a sinker once again. While the average velocity thus far isn’t anything to brag about (93.1 mph, 29th percentile), he demonstrated some improvement with his four-seam in terms of spin, active spin, and total movement.

Beyond the stuff, Teng does offer a different look than what we’re used to seeing from Houston pitchers as of late, as his 24-degree average arm angle would be among the lowest on the staff. Of the 36 players to throw a pitch last season for the Astros, only seven had a lower average arm angle than 24 degrees. While a difference in arm angles by itself doesn’t mean success or failure, it certainly offers a different look to opposing hitters. For example, seeing Hunter Brown, with his average arm angle of 56 degrees, for two to three times through the order, followed up by Teng’s mechanics, would be interesting to watch.

But for him to succeed, the Astros have to help Teng improve his command. Walking 17 in 29 2/3 innings, for example, is a problem. And when we look at heatmaps, you can easily see how much his pitches bleed out of the zone.

Overall, though, there is plenty to like about Teng even with his problematic command issues. The sweeper is legitimate. Generating strikeouts hasn’t been an issue. Regardless of his ultimate role, he does offer another arm with some interesting qualities that could prove beneficial to a staff if his weaknesses are somewhat mitigated.

Photo provided by Pixel Pete