If I told you the Yankees had a lefty pitcher whose fastball averaged 90.4 miles per hour (14th percentile) and whose fastball spin rate ranked in the 38th percentile, what would you think? I don’t think it’d be positive. You’d likely think it was a last-guy-in-the-bullpen situation. Enter Néstor Cortes, Jr. Despite those lowly ranks in things we might look for in a strikeout pitcher, Cortes ranks in the 68th percentile for strikeout rate and the 75th percentile for hard hit percentage. He’s been nothing short of amazing and was instrumental in helping the Yankees not only right but turn around the ship.
In 2021, Cortes has thrown his fastball 387 times to great, great success. To date, the pitch has a .165 BA against (.145 expected), a .224 SLG against (.226 expected), and a .222 wOBA against (.210 expected). It’s been his put away pitch 24.6% of the time and sports a 34% strikeout rate. All told, that adds up to 11 runs of value (Statcast calls this -11, but you get the idea), which ranks 14th in all of MLB (minimum 300 fastballs thrown). Part of the reason is location. Look at this plot of Cortes’ fastballs:
Lots of fastballs up and just out of the zone. These are locations, especially that red zone (87), in which it’s hard to put a good swing on the ball or make good contact. This is ironic considering his relatively low velocity and spin rate on fastballs. Typically, it’s high velocity and/or high spin rate fastballs that do damage to batters up in the zone. But, somehow, Cortes is doing it. Here’s his strikeout chart on fastballs:
Some big numbers appear in those out of the zone boxes at the top of the chart. One way or another, Cortes is getting batters to miss on well-located pitches. Maybe they think his ball is easier to hit because of the low velocity. Or maybe his changing rhythms and occasional deception in delivery are fooling batters. Either way, it’s working, even when they make contact. Remember that .222 wOBA mark against the pitch? Here’s what it looks like by zone:
Again, look at the numbers up in the zone and just out of it. He’s having great success with the high fastball, despite not appearing to have a fastball that would succeed up in the zone.
No matter the reason, Néstor Cortes has been a revelation for the Yankees this year. Their philosophy of working fastballs up in the zone has rubbed off on him, so that’s a credit to both a sound strategy and a pitcher who’s making it work. Nasty Néstor, indeed.