Do pitch tunnels help explain the frustration of Michael Pineda and Nathan Eovaldi?

Last week, the team at Baseball Prospectus unveiled a host of new pitching metrics. The new data attempts to quantify certain concepts like command, control, and deception in a more concrete way. I’d highly encourage you to read through BP’s analysis to get a full scope of what these numbers illustrate.

In short, BP has devised called strike probability, or CS Prob, as a measure of control. CS Prob represents the probability any given pitch a particular pitcher throws will be a strike, adjusted for count, batter, and the strike zone actually called by umpires (as opposed to the rule book strike zone).

Called strikes above average, or CSAA, is BP’s proxy for command. Command differs from control, in how control is generally considered to be the ability to throw strikes, while command is the ability to hit specific spots in the strike zone. CSAA measures how many strikes a pitcher generates above and beyond what would be expected based on their CS Prob.

The concept of pitch tunnels was also introduced. Pitch tunnel data essentially tries to demonstrate how deceptive a pitcher can be. Based on the speed of an average fastball, hitters have to decide whether to swing when the ball is about 23 feet from the plate. Pitchers who maintain tight pitch tunnels throw pitches that look very similar from the release point all the way to the tunnel point, which is 23 feet from home.

These metrics open up worlds of possibilities with regard to analyzing pitchers. It’ll take plenty of time before we really understand how predictive and descriptive these figures are, but for now, we can take some surface-level views of them to try and answer some broad questions. One such question: do these numbers help explain the Yankees’ most enigmatic 2016 pitchers, Michael Pineda and Nathan Eovaldi?

Some of the intuition behind BP’s new metrics is the idea that there must be a reason that certain pitchers, like Kyle Hendricks, can succeed with unimpressive stuff. Similarly, there must be a reason that players with dazzling stuff, like Pineda and Eovaldi, only yield middling results.

Let’s start with command and control. It would be natural to assume that Pineda and Eovaldi possess solid control, pounding the strike zone with their overpowering fastballs, helping them post low walk rates and shiny FIPs, albeit while lacking command and the ability to throw good strikes.

What does the data say? Out of 138 pitchers who threw at least 100 innings in 2016, Pineda ranked 114th in CSAA, with a figure of -0.8%, and Eovaldi ranked 121st, with a figure of -1.0%. That means that Eovaldi received 1% fewer called strikes than would be expected based on his CS Prob. That might not seem like a lot, but over the course of a season and thousands of pitches, those extra strikes add up.

It does seem like Pineda and Eovaldi lack the skill to paint the corners and command their stuff, but do they pound the zone with good control? Among those same 138 pitchers, Eovaldi ranked 18th with a CS Prob of 49.2%, while Pineda surprisingly ranked a lowly 114th, at 44.5%.

So our intuition regarding Pineda and Eovaldi’s control/command conundrum is mostly, but not completely, correct. Neither has quality command, and Eovaldi does stay in the strike zone, but Pineda actually doesn’t throw many strikes in general. Pineda lacked control and command last year, but still struck out 10.6 batters per nine. Does this mean that perhaps Pineda generates swings and misses due a high level of deception?

That would seem a bit odd, since Pineda is a pretty straightforward two-pitch pitcher who doesn’t really keep hitters in suspense about what’s coming. Pitch tunnels could offer a clearer picture though.

To understand pitch tunnel metrics, we need to grasp a few different statistics. The first is release differential, or the average difference in release point between a pitcher’s consecutive offerings. Then there’s tunnel differential, or how far apart a pitcher’s offerings are at the aforementioned tunnel point. There is also break differential, or how much a pitcher’s pitches break after the tunnel point.

The average release differential among starters who threw at least 100 pitches last year was 2.38 inches. Pineda’s release differential was a solid 2.08 inches, which means Pineda’s pitches weren’t easy to discern just based off his release point. The average tunnel differential was 10.03 inches, while Pineda’s was 9.78 inches. Again, Pineda was better than average at hiding what his pitches were as they reached the tunnel point. Pineda’s break differential was 2.72 inches, compared to the 2.78 inch league average, so his pitches broke a tad less than average after the tunnel point.

Likewise, Eovaldi’s release differential was a very poor 3.26 inches, while his tunnel differential was worse than average at 10.33 inches. His pitches also only averaged 2.40 inches of break after the tunnel point.

So there are some interesting, 30,000-foot findings here. Pineda comes out looking fairly good. Coming into this, I would have guessed that a lack of deception, an inability to disguise the difference between his hard cutter and biting slider, might contribute to Pineda’s struggles. However, Pineda ranks much better than average at blurring the lines between his offerings.

Eovaldi, on the other hand, fed right into the preconceived notions that I, and surely many other Yankee fans, previously held. He has electric velocity, but Eovaldi seemingly does a bad job disguising his pitches. Couple that with his strike-throwing tendencies and lack of command, and you would seem to have a recipe for a pitcher with tantalizing stuff and mediocre results. It’s unclear if Eovaldi will ever appear in pinstripes again after being released in wake of his Tommy John surgery, but if he wants to truly succeed in the majors, then he clearly has work to do.

Pineda, as usual, feels more confounding. He doesn’t stay in the strike zone nearly as much as one might think, and pitch tunnel data actually paints him in a rosy light. As always, we will stay vigilant in trying to crack the puzzle that is Pineda, and BP’s fascinating new numbers help us get a step closer. But with potentially just one year left of his Yankee tenure, time might be running out to get to the bottom of Pineda’s perpetual cycle of frustration.