After winning their first postseason game since 2009, the Colorado Rockies will begin the National League Division Series on Thursday afternoon. In game one of the series, the Rockies will hand the ball to 23-year-old righty Antonio Senzatela. With German Márquez and Kyle Freeland each unavailable, Senzatela is a perfectly good choice to start this game. His park-adjusted ERA- and FIP- each rate slightly better than league average, and his Expected wOBA (xwOBA) comes in tied for 75th among 147 pitchers who have thrown at least 1,500 pitches this season.
In his past three starts, Senzatela has turned it up a notch, posting a 1.62 ERA and limiting opposing hitters to a .213/.273/.361 slash line across 162⁄3 innings. The Rockies have won all three games. In those three starts, Senzatela’s xwOBA has dropped from .339 to .281. For context, that’s essentially the same as the difference between Gerrit Cole (.283 xwOBA) and Dylan Bundy (.341 xwOBA) this season. Are we looking at nothing more than small sample size randomness, or has Senzatela figured something out?
To try and determine which it is, let’s take a look at the xwOBA of each of Senzatela’s four pitches—4-seam fastball, slider, curveball, and changeup—compared to the league average for right-handed pitchers on each pitch, as well as his usage of each pitch across his first 20 appearances this season compared to his last three.
Antonio Senzatela pitches compared to league average
| Pitch Type | Senzatela xwOBA | League xwOBA |
|---|---|---|
| Pitch Type | Senzatela xwOBA | League xwOBA |
| 4-seam fastball | 0.371 | 0.364 |
| Slider | 0.273 | 0.269 |
| Curveball | 0.131 | 0.267 |
| Changeup | 0.260 | 0.291 |
Antonio Senzatela pitch usage
| Pitch Type | Through 9/11 | After 9/11 |
|---|---|---|
| Pitch Type | Through 9/11 | After 9/11 |
| 4-seam fastball | 65.8% | 54.3% |
| Slider | 21.1% | 8.2% |
| Curveball | 5.9% | 20.7% |
| Changeup | 7.1% | 16.8% |
A few things likely jump out at you here. First, Senzatela’s curveball has been not just good, but great. In fact, his xwOBA of .131 on curveballs is the best among all right-handed pitchers who have thrown at least 1,500 total pitches and at least 100 curveballs. Moving to the second table, the usage of Senzatela’s curveball has spiked from 5.9% all the way up to 20.7% in his last three outings.
We see something similar with Senzatela’s changeup—his other pitch that has been better than league average this season—as the usage of that pitch has jumped from 7.1% up to 16.8% in his last three starts. Add that to his curveball, and Senzatela has gone from using his two above average pitches 13% of the time for the majority of the season all the way up to 37.5% of the time in his last three starts. With a change like that, it’s no surprise he’s seeing improved results.
Purple Row’s Sam Bradfield recently caught up with Chris Iannetta—the starting catcher in each of Senzatela’s last three starts—to ask him about the change. “Just consistency. I think he’s a little more consistent with (the curveball and changeup) than he is with his slider.” said Iannetta. “So we’re really cautious on when we’re using it now just because his curveball and changeup have been so good he doesn’t have a necessity for it.”
Iannetta expanded on the thought process behind the change in Senzatela’s repertoire of late:
Execution’s kinda the name of the game. You just, it doesn’t matter which pitch you throw sometimes just as long as it’s executed. Like the old adage is “an executed pitch is more important than the right pitch.” Scouting for the situation might call for a certain pitch but if it’s not executed it’s not a good pitch, you know. If he can’t hit a slider down and away and that’s the right pitch that you’re trying to throw and you leave it up over the middle of the plate, a Major League hitter is going to have a pretty good leverage on that pitch. So if you can execute a fastball down there, you can execute a curveball or a changeup down there, and it’s executed, batting average against is much lower so you go with those pitches over something that’s the “right pitch.”
Seemingly, Senzatela has made the determination that it’s best to focus on his strengths as opposed to the hitter’s weaknesses. If he’s confident in his ability to execute a curveball, he’s going to throw a curveball, even if the batter’s scouting report suggests another pitch would be a better option.
As Adam Peterson noted in last season’s Ranking the Rockies series, the biggest question mark with regards to whether Senzatela will be able to stick as a starter long-term has been his ability to develop legitimate secondary pitches to work with beyond his fastball. If what we’re seeing is real, he may have taken a step toward becoming another legitimate threat in the Rockies’ starting rotation.