[Fangraphs] The Astros May Have Salvaged Another Pitcher’s Career

EXCELLENT article about how the Astros analyze pitching and use it to improve the players.


The Astros May Have Salvaged Another Pitcher’s Career

by Jake Mailhot
August 5, 2019

You knew it was coming. When Houston acquired Aaron Sanchez from the Blue Jays, changes to his repertoire were bound to follow. By now, the pitching preferences of the Astros organization are well known: throw your best pitch more often and ditch your worst. It’s not as simple as telling pitchers to throw more breaking balls or throw fewer fastballs, though. It’s an individualized pitching strategy based on the strengths and weaknesses of the particular pitcher. Erstwhile FanGraphs author Travis Sawchik describes how these individualized development plans are presented to new Astros in his new book, The MVP Machine, co-authored with Ben Lindbergh:

When you're traded to the Astros, this is what your first meeting with the club is like (via a nonfiction book titled The MVP Machine):





We may have expected some tweaks, but I’m not sure anyone could have expected the adjustments to have such an immediate impact for Sanchez. With the Blue Jays, he had posted a league worst 6.07 ERA with a 5.03 FIP across 23 starts. In his first start with his new team, he held the Mariners hitless over six innings, allowing just three base runners and striking out six. Will Harris, Joe Biagini (who came over from the Blue Jays in the same trade), and Chris Devenski completed the combined no-hitter after Sanchez was lifted after the sixth.

Just a quick look at Sanchez’s pitch arsenal gives us a pretty good idea of what the Astros wanted him to do in his first start. Below, you’ll see the individual components of Sanchez’s pitches, and their percentile rank when compared within each pitch type:


Aaron Sanchez, Pitch Type Characteristics, Percentile Rank
Pitch Type Frequency Velocity Horizontal Movement Vertical Movement Spin Rate

Four-seam 28.7% 75 90 31 67
Sinker 29.5% 81 71 31 81
Changeup 19.6% 8 85 63 65
Curveball 22.3% 51 84 84 93

This season with the Blue Jays, Sanchez had been throwing his four-seam and sinking fastball around the same amount. Historically, he’s heavily favored his sinker, throwing it over half the time earlier in his career. Based on their raw characteristics, there’s very little separating the two fastballs. His four-seam does possess elite horizontal movement but that’s not usually the type of movement the Astros have tried to elicit from their pitchers. And the ride on his four-seamer is rather lackluster, likely related to the average spin rate the pitch possesses.


But his curveball is a thing of beauty. It’s movement profile is well above average, both vertically and horizontally. The thing that really makes it stand out is its elite spin rate. Given the raw inputs, we can calculate how much of that spin contributes towards the movement profile of Sanchez’s curveball; thanks to Statcast, that complex physics calculation is already done for us. Sanchez throws his curveball with 89.8% active spin — spin that’s contributing to its movement — a mark that places the pitch in the 93rd percentile among all curveballs thrown in the majors.

In his first start with Houston, Sanchez threw his curveball 30.4% of the time. In his career, Sanchez has thrown his curveball more than 30% of the time in a single outing just twice, and both times were in relief appearances during his rookie year back in 2014. On Saturday, Sanchez generated five swinging strikes with his bender, a 45.5% whiff rate. He also earned six called strikes with the pitch, giving him a called plus swinging strike rate of nearly 40%, elite for a breaking pitch.

Besides highlighting his curveball, Sanchez also cut down on his sinker in favor of his four-seam fastball. He threw his four-seamer 32.6% of the time, higher than his season average but not close to his season high. The Astros definitely have a preference for four-seam fastballs, especially when paired with a vertically breaking curveball. A riding fastball tunnels much better with a curveball than a sinking fastball does. Of course, the location of those four-seamers matters to creating that pitch tunnel and it looks like Sanchez listened to the Astros preferences for high heat.



The average vertical location of Sanchez’s fastball against the Mariners was 2.3 inches higher than his season average. He generated two swinging strikes and nine called strikes with his heater, a whiff rate of 25% and a called plus swinging strike rate of 37%, both marks well above average for a fastball.

The first at-bat of the evening was a perfect example of his approach with these two pitches. Facing Mallex Smith, a left-handed batter, Sanchez started off the game with a fastball low and in for a called strike. He followed that up with a sweeping curveball in nearly the same location for strike two. That pitch was particularly bold since it broke across the strike zone, but Smith appeared to be caught completely off guard. The third pitch was another curveball in the same spot that Smith barely fouled off. Next, he changed Smith’s eye level with a four-seamer up and in for ball one. You could probably guess where this is going next. He came back with curveball, low and in again, and Smith swung right over the top.



It really shouldn’t be this easy, and maybe it won’t be; this was just Sanchez’s first start in an Astros uniform, after all. But as first starts go, six no-hit innings is pretty good. The changes the Astros have asked him to make are already apparent. He’s throwing his elite curveball more often and swapping the usage of his sinker for more high four-seam fastballs. It’s as straightforward as a plan can get. Assuming this kind of performance continues, you can add Sanchez’s revitalization to the laundry list of pitchers the Astros have helped. His immediate success with his new team makes you wonder why the Blue Jays failed to extract these kind of results from someone with his talent.

What the Astros are asking of their pitchers isn’t rocket science, but for some reason, they’re unlocking latent talent in their pitchers where other teams have failed. With Zack Greinke also in the fold, it looks like the Astros have solidified their rotation in their quest to win a second World Series in three years.