The news of yet another Mets star going down for a significant period of time (the rest of the season, actually) will hopefully put to rest the hopes of those few Mets fans who were still clinging to the possibility of a wild card run. Despite being 11 games under .500 and 14 games out of the wild card, there are always those fans who irrationally cling to their dream of October glory. You’ve seen ‘em, I’ve seen ‘em. It’s sad.
There was talk around two years ago about Johan Santana being reluctant to throw his slider to alleviate the pain in his elbow, and he did cut down significantly on his slider at the end of 2007. Looking at his pitch types on FanGraphs, at least the second part of that looks to be true. In 2007 he started throwing his slider about 11 times per 100 pitches, compared to the 16-20 times per 100 pitches that he had been throwing it the previous four years. The reason he’s been able to essentially cut out such a good pitch is because his changeup has been so good over the years. Year in and year out until now, it’s been essentially a two-win pitch. With a pitch that good, you don’t need much else.
You do, however, need a healthy elbow to pitch and pitch effectively. The problem with throwing a slider is that it is often thrown with a supinated grip through release. This means that as the pitch is released, his left pinky is closer to the ground than his index finger. The correct grip through release of any pitch is a pronated grip. You can tell fairly accurately that a pronated release is occurring when your index finger is closer to the ground than your pinky finger at release. Think of it like this: supination looks like you’re shaking someone’s hand, pronation is when your thumb points to the ground. You can see the beginnings of what I mean in this video, but it gets cut off a little early. For a lefty like Johan, that means his palm is facing third base at release instead of first base. Now it’s hard to know if this is exactly what’s happening with him without looking at high speed film. But his injury is consistent with this motion.
With a supinated grip through release, his olecranon process will slam into its fossa as he releases the pitch, which can lead to a few things: cartilage irritation, lengthening of the humerus, and bone spurs, among others. The third one is what we care about here, as it has happened to Santana previously, early in his career. He might have to scrap the slider entirely if elbow irritation and other issues persist in the future, which would be a blow to his value as a pitcher. Successful two-pitch pitchers in the starting rotation are few and far between, so this is definitely something the baseball world should be keeping an eye on. But succeeding with just two pitches isn’t something I would put past a guy with the talent of Johan Santana.