The cruelest month is over, and although most breakouts still aren’t real and most bad teams still have time to turn things around, we can finally say that anything going on in baseball has lasted for the full first month of the season. We also have a chance to survey the various leaderboards (we have so many leaderboards now! This is The Golden Age of Leaderboards) to see if anything really leaps out at us.
And hey, something does! (I’m as surprised as you are.) When you sort our leaderboard for Called Strike Probability (CSPROB, for short, one of the new suite of stats we broke out earlier this year to analyze pitchers), with a minimum of 20 innings pitched on the year, the guy at the top is the Rockies’ rocket-armed rookie righty, Antonio Senzatela. In other words, of the 124 pitchers who have pitched most over the first month, no one has been around the zone more than Senzatela. For a rookie, that’s impressive. For a guy who pitches his home games in Colorado, it’s doubly impressive. For a rookie who pitches his home games in Colorado and all games in the most homer-happy era of the major leagues we have ever known, it’s arguably even more impressive.
Senzatela’s surface-level stats (2.81 ERA, 1.00 WHIP, 2.57 strikeouts per walk) are impressive, too. From FIP (4.16) to cFIP (114) to DRA (7.30, for a DRA- of 165), though, advanced metrics say his success has been nothing but smoke and mirrors. That’s kind of interesting, especially in the case of a rookie, because it suggests that (though we now have five big-league starts on which to judge him, whereas we had zero before Opening Day) we still know almost nothing about the man.
That isn’t true, of course. We know a lot, by now. The stats that judge Senzatela at a valuation level will take much more than this meager month to render their final verdict. It’ll take even more than this season. While we wait, though, we have an abundance of information pouring in to help us make an evaluation of various aspects of the Venezuelan right-hander. Let’s dig into it.
The first thing you ought to know about Senzatela is that he isn’t an especially big guy. He stands 6-foot-1, according to Baseball Reference, and weighs 180 pounds. On the height side, that might even be a tad optimistic. The second thing I can tell you, based on his April starts, is that he has a simple, quiet, and fairly straight-ahead delivery. He starts with his feet shoulder-width, square to home plate, brings his left foot back in a rock step, then sweeps smoothly up and into his motion. His hands never go above his head. He never turns his back to the batter. From the windup, he slightly counter-rotates during his leg lift, and his front side (specifically the glove hand) is a bit higher than most pitchers’, but his stride is ultimately pretty straight.
Because of the timing pattern created by those small quirks, he locates his stuff (especially his fastball) much better to the arm side (third-base side) of home plate than to the glove side (first base). He doesn’t throw across his body. In fact, he gets good extension from a fairly high arm slot: Of the 119 pitchers who have thrown at least 300 pitches this season, Senzatela has the 13th-highest perceived velocity on his fastball, according to Baseball Savant. (He ranks 23rd in raw average velocity.) That fastball is his bread and butter. Senzatela ranked alongside the likes of Bartolo Colon, Ivan Nova, and Lance Lynn as the most fastball-reliant starters in baseball over the first month. It makes sense, though, because few pitchers have any comparable weapon on which to lean.
It’s not just velocity, or even deception or command. (Indeed, while his control is quite good, his command of the fastball is a bit behind right now. More on that in a minute.) Senzatela’s four-seamer has more cutting action (or less tail—tomato, tomahto) than all but two other qualifying pitchers (32 of them, for these purposes) this year: Zack Greinke and Clayton Kershaw. It also sinks more (rises less) than the fastballs of all but four other hurlers on the list: Sean Manaea, Adam Conley, Max Scherzer, and Julio Teheran. His spin rate is significantly below average for a four-seamer, helping achieve that peculiar movement.
Senzatela isn’t missing bats with his fastball. No pitcher who throws their four-seamer so much got so few swinging strikes on it in April. What he is doing, though, with that low-spin laser that pounds the zone but tends to find the bottoms of bats, is inducing grounders. Only Manaea and Robbie Ray have higher ground-ball rates on four-seamers this season. If you wanted to explain how Senzatela has had success so far without fully admitting the role of randomness and unfamiliarity, this would be the way to do it. It’s an unusual trick to throw a four-seam fastball that consistently induces grounders, but Senzatela seems able to turn it.
If all Senzatela had was an unusually hard fastball, coming out of a modestly deceptive delivery, with unusual movement and the ability to get weak contact because of it, that’d be neat. A lot of pitchers don’t have anything as interesting as that into which we can dig. Happily, though, there’s even more to examine with Senzatela. Let’s talk tunneling.
Recall that in February, along with CSPROB and CSAA (our estimates of control and command, or at least catchability), we rolled out numbers that attempt to capture the value of sequencing and repeating one’s delivery. Tunneling is, essentially, using the batter’s inability to track the full flight of the ball from the pitcher’s hand to the plate as a weapon. If a hurler can throw consecutive pitches out of the same arm slot, with something close enough to the same speed to keep the hitter from recognizing the difference right away, and with a similar enough initial flight path to convince the hitter (even if only subconsciously) that the same pitch is coming, he can induce bad chases and/or empty swings.
There are a bunch of ways to tunnel effectively. Some guys excel at repeating their delivery, down to the precise release point, no matter where they’re throwing a pitch or even which pitch they’re throwing. Others get so much movement on their breaking stuff or changeups that they can throw the pitch on the same plane and from the same place as their fastball, and still end up putting the ball in such a different place by the time it gets to the hitting zone that batters swing and miss.
Senzatela does not, on average, throw his slider from one arm slot and his fastball from another. In fact, his average release points for his three pitches (fastball, slider, changeup) are quite close to one another. However, from pitch to pitch, he doesn’t repeat his release point very closely. Anecdotally, I’d suggest that he aims the ball a bit when he’s trying to throw one pitch to a different part of the zone than the part to which he threw the previous one, and that can change his delivery slightly. He especially seems to adjust his arm angle when he’s trying to throw to the first-base side, overcompensating for the slight closure of his stride. What he doesn’t do, though, is give himself away. That’s because he’s as likely to vary his release point on back-to-back fastballs as he is when transitioning from a fastball to something else.
Ninety-one pitchers have thrown a four-seamer, followed by another, at least 50 times this year. (Senzatela has done it a league-high 200 times.) Of those, the only pitcher whose release point varies more than Senzatela’s does, from one fastball to the next, is Eduardo Rodriguez. There are also only two pitchers who vary the speeds on consecutive fastballs more than he does: Chris Sale (whose apparent endeavor to do this I chronicled during spring training) and Brent Suter. So although he’s not good at disguising his slider as his fastball (for four-seamer-slider sequences, he’s in the upper quartile of the league in release-point differential, and even higher in terms of the differential in location when the ball reaches the tunnel point), Senzatela throws hitters off by not having a consistent enough release to even allow them to look for tipped pitches.
He also has good overall movement on the slider. It’s a pitch that can be as little as 10 miles per hour slower than the fastball, or as much as 17 miles per hour slower, so hitters can try to read the spin, then the speed, but his post-tunnel break is still good enough to get a hitter to make weak contact. Of the 86 pitchers who have thrown a four-seamer, then a slider at least 20 times this year, Senzatela’s average post-tunnel break differential for the sequence is the seventh-widest.
There’s a lot we don’t yet know. There are a lot of samples that are too small to make definitive or final determinations of what kind of pitcher Senzatela will be, and a lot of opportunities for him to develop and change lie ahead. He’s been throwing a ridiculous number of fastballs in home games, not trusting Coors Field just yet to make his fringy secondary stuff playable. He’s adding and subtracting on all three pitches throughout his outings, but not always seeming to do so with a strategic plan. As he’s turned over lineup cards and gotten into the 70s in his pitch counts, he’s seen his fastball speed drop from 94-96 (touching 98) to 91-93 (touching 96). He’s still fighting to find a rhythm on the mound when there are runners on base, and his delivery doesn’t have as much momentum or torque out of the stretch right now. He’s not holding runners on base especially well.
His catchers are not comfortable, just yet, setting up for and presenting those fastballs on the edge of the zone to the arm side, and he’s being squeezed as a result. On the other hand, not repeating his release point well and having a fastball with such unusual movement works against Senzatela on that front, which is reflected in his poor -2.18 percent in CSAA (our new proxy for command). He’s only faced one team (the Giants) twice. His only really tough start was against the Nationals, and he actually weathered the storm that is their juggernaut lineup quite well. Opposing batters have about a league-average aggregate exit velocity against him, but that’s without an adjustment for the fact that they’re playing at Coors, and it comes with a well below-average aggregate launch angle. We know, then, that Senzatela has minimized damaging contact. It’s way too early to assume that he’ll do so consistently.
It’s funny to see such a young and inexperienced pitcher do so many things at an advanced level. Senzatela’s presence on the mound is downright serene—unflappable is not too strong a word. He’s manipulating each of his pitches so well that I spent some time trying to tell whether his fastball is actually two different fastballs, but if it’s so, that distinction doesn’t seem to have been publicly noted, and the data doesn’t quite give it away. It’s delightful that our new pitching stats highlight him in two distinct ways. It also creates a tension, one that grows from the gap between the value metrics’ low estimation of him and the indicators pointing in the other direction at a more granular level.
All of the leaderboards, and all of the newfangled numbers they allow us to sift through, take most of the season to yield a reliable measurement of the best and worst in the game. In as little as one month, though, they can provide an even more valuable service: helping us find players to whom we should pay more attention, if only for our own enjoyment and education.