Continuing to fix Jonathan Loáisiga

Through the first month-plus of the season, the most common line of praise we heard about the Yankees was how dominant the relievers had been. All of a sudden, the Yankees bullpen isn’t as bulletproof as it appeared even two weeks ago. With Chad Green done for the year needing Tommy John surgery and Aroldis Chapman unplayable in high leverage situations while he deals with Achilles tendonitis, reliever depth is starting to look thin. But the most worrying aspect of the bullpen has been the complete and utter regression of Jonathan Loáisiga from the team’s best reliever last year to a barrel-finding blowup waiting to happen this year.

Last Monday, Esteban penned a remarkable piece investigating Jonathan Loáisiga’s early season struggles. He analyzed every part of the reliever’s pitcher profile in an attempt to diagnose the issues and potentially prescribe a cure. If you haven’t read it already, I strongly recommend it as required reading for all members of the PSA community, but the main findings revolved around a slight alteration in Loáisiga’s release point on the sinker, causing the pitch to enter the zone at a different Horizontal Approach Angle (HAA) and find barrels at a much higher rate relative to last year.

The sinker is Loáisiga’s bread-and-butter pitch — he throws it almost 60 percent of the time, to both righties and lefties, and in any count. As Esteban found, there is very little to separate his 2021 sinker from the 2022 version. The velocities are within one mile per hour, the movement profiles are the same, his command of the pitch — for the most part — mirrors that of 2021, the average exit velocities are almost identical. The only difference on the pitch is a raise in average launch angle from -5 to +5 degrees — also reflected in a decrease in groundball rate and a rise in line drive rate. For a hard-throwing sinkerballer who pitches to contact, you can see how having roughly 20 percent of his groundballs from a year ago getting converted into line drives could be devastating.

Esteban concluded that the change in release point was causing Loáisiga’s command to falter and lose too many pitches arm-side, middle. Indeed, that is where the majority of hits have come against his sinker so far in 2022.

However, I find that explanation on its own to be unsatisfactory. Loáisiga is landing essentially the same percentage of sinkers — 20.6 percent in 2021, 22 percent in 2022 — in the arm-side, middle zone, so I think we have to look further. Esteban also posited that the slight deviation in HAA from a -0.2 degree entry angle to a a +0.3 degree entry angle was causing the pitch to break at the wrong time and ultimately run into too many barrels. I think he could be onto something here, so I dug through the video archives of sinkers from last year versus this year to see if that indeed was happening.

Here is a middle-middle sinker thrown against Michael Brantley in 2021:

And here is a sinker in the exact same location, this time thrown against Yoán Moncada two weeks ago:

Both pitches are thrown with roughly similar velocity and total overall movement, but with wildly different results. Brantley pounds the sinker into the ground for an easy out whereas Moncada crushes his sinker 417 feet to left. To echo what Esteban said in his piece, we are talking about minute differences on the magnitude of millimeters, but I think you can begin to see what he was talking about with the effect of the altered HAA.

Against Brantley, the sinker is achieving its maximum rate of break right as it enters the zone. This makes it incredibly difficult for even one of the most revered hitters in the game to match his barrel to the ball’s path. In contrast, against Moncada it’s almost like the sinker has completed most of its break before reaching the plate, such that it is flat as it enters the hitting zone. This makes it much easier for Moncada to track the pitch and put his barrel on it.

Here is a another example, this time a sinker thrown arm-side, middle to Anthony Rendon in 2021:

And here is a sinker thrown in the exact same location against Vladimir Guerrero Jr. back in April:

Again, I think we can start to see why Loáisiga’s sinker has been much easier to barrel this year. Granted, the pitch thrown to Rendon is 3.5 mph slower so by no means are these perfect analogues. However, it appears we see a repeat of what happened in the previous examples. The sinker to Rendon takes a sharp right hand turn right as he’s about to make contact and he gets jammed. Contrast that with the sinker to Vladito, which almost appears to be straightening out as it approached the plate, making it that much easier for the Toronto slugger to get his barrel to it.

Is all this just a case of confirmation bias? Am I choosing to interpret what my eyes see in a way that supports our hypothesis? That could very well be so. Whatever the case may be, I’d just like to finish with two closing thoughts.

First, Loáisiga is a perfect example of the volatility of relievers. Pitching to such such small sample sizes lends itself to skewed results not always indicative of true talent level. Really, his dismal start to the season can be boiled down to basically half a dozen sinkers that got punished this year but weren’t punished last year. Be that as it may, I think his case should serve as a reminder to pitching departments everywhere that success out of the bullpen is fleeting and there should be a constant effort to develop the next wave of arms as existing ones lose effectiveness.

Second, I think this investigation and the one Esteban conducted illustrate how important it is to consider all pieces of evidence before us. A greater number of Loáisiga’s metrics — spin rate, velocity, movement, command, etc. — suggested that he’s the same pitcher as last year than there are that suggest something has changed. Obviously, we know that not to be the case. Every stat and metric is a small piece of the puzzle, and you cannot see the full picture without every piece in it’s place.