Luis Cessa has put it together at last

There are a few things that you may or may not have noticed about Luis Cessa over the past few seasons. For example, he’s quietly become a pretty good pitcher and a valuable member of the Yankees, for starters.

First and foremost, he’s consistently improved over the course of his career, which is now in its sixth season. As a pitcher who has never been a big swing and miss type, and therefore has never had an impressive strikeout rate, some of the more common statistics used for relief pitchers don’t adequately give him his due. However, 2021 is the fourth season in a row for Cessa in which his ERA has dropped and this is the third straight season in which his adjusted ERA (ERA+) and FIP have improved. Additionally, his Statcast expected ERA (xERA) ranged from between 4.54 to 5.60 in his first three seasons, and between 3.56 and 3.93 in the three seasons since. He’s also in the middle of his third straight season in which he added to his team’s win probability, after three seasons of deducting from it.

If you’re curious what the driver behind the improvement has been, you don’t have to look far. Quite simply, his fastball has never been very good, and he started throwing it less frequently. Conversely, his slider has always been very good, and he’s greatly increased its usage. Check the chart below that shows the percentage of times he’s thrown each pitch per season:

One does not need to be a mathematician from MIT to spot a trend in those number sequences. There’s been a steady increase in slider usage with a corresponding decrease in fastball usage. But can it be something else, like improved command perhaps?

Not really. These are the heat maps for his slider and fastball for the 2016, 2018, and 2021 seasons — tell me if you notice anything:

I selected those three seasons to cover a large span of time and for brevity, but if you’re curious, his other three seasons look very similar to these. As you can see, throughout Cessa’s career, his slider has shown a propensity for staying down and in to left-handed batters (down and away to right-handed batters), which obviously is a good thing. However, his fastball has the proclivity to find the center of the zone pretty consistently, which of course, is not good.

If you look real hard to spot any difference, you may notice that as his career has progressed, his fastball, although still ending up mid-zone far too often, ends up middle-up less often than it used to. (When you average 99 mph on your four-seamer, up in the zone may work — if you average 93 mph as Cessa does, not so much.) This, combined with the increase in slider usage may also explain Cessa’s current 56.8 groundball rate which is easily his career-best, and also a career-best in average exit velocity allowed, which currently ranks in the 89th percentile in MLB.

If you’re curious about his spin rate, as I was, it hasn’t been much of a factor. His slider spin rate has trended upward slightly over six seasons, but his 2021 rate is only the third-highest of his career by a small margin. And although his vertical movement on his slider has improved, it essentially went from good to very good — probably a factor in his improvement but not as significant as simply throwing your good pitch more and your bad pitch less.

What Luis Cessa has quietly evolved into is a pitcher who issues few walks and consistently generates weak contact. The result is that he’s been a better-than-league-average pitcher going by both traditional ERA and ERA+ since 2019. In fact, if such matters interest you, according to FanGraphs he’s been worth more than double what the Yankees have paid him over the past three seasons when on-field value is converted to dollars.

So how does a clearly valuable asset get overlooked to the extent Cessa has? There are three reasons:

First, being a good relief pitcher will get you noticed on most teams, but not on the Yankees. Of all the critiques you can make of the Yankees over the past five years or so, the bullpen isn’t one, as it’s been among the game’s best. Dellin Betances, David Robertson, Andrew Miller, Tommy Kahnle, Zack Britton, Chad Green, Jonathan Loaisiga, and Aroldis Chapman have all had stretches of dominance in pinstripes while Cessa was in the pen with them. It’s pretty easy to see how a merely “good” pitcher can be overlooked in that setting.

Secondly, middle inning relievers, in my mind anyway, are underrated in general. If you’ll allow me to put on my amateur sociologist cap for a moment, I believe most fans place far too much importance on the sequence and timing of events in a baseball game. The runs that are allowed in the second inning, the sixth inning, and the ninth inning all count the same on the scoreboard. If a pitcher enters the game with his team trailing by between one and four runs between the fifth and eighth innings, that is an unglamorous, but crucial spot.

A pitcher entering that situation is the difference between the team having a chance to come back and win or discussing after-game dinner plans in the dugout between innings. Often the pitcher has to throw more than one inning, often when inheriting runners, and against the middle of the other team’s lineup. If you have someone who fills that role with better than league average performance — which by definition gives you a competitive advantage more than half the time — you’ve got yourself a valuable player.

And if you’re curious how Cessa has done in this specific scenario this year, he’s faired well. Cessa has appeared in games with the Yankees trailing by between one and four runs, between the fifth and eighth innings in almost half of his appearances, has pitched more than an inning in more than a third of his appearances, and entered with runners on base in one-quarter of his appearances.

Finally, Cessa blends in because he’s simply just done his job, and he’s done it well. He hasn’t “wowed” us and made us run to social media the way Gerrit Cole, Jonathan Loaisiga, and Aaron Judge have this season and he hasn’t vastly underperformed like (well, you can pick seven or nine Yankees to finish this sentence) has.

If he’s under-appreciated, that’s on us, because he’s holding up his end of the bargain and then some.