CC Sabathia has a new trick in his bag:

Andy Pettitte did more than simply watch CC Sabathia’s bullpen session on Monday. The guest instructor actively instructed, primarily helping to teach Sabathia a cut fastball, something the Yankees’ ace hopes to add to his repertoire this season. “He was showing me a grip with the cutter,” Sabathia said after throwing a four-inning simulated game indoors at Steinbrenner Field because of heavy rain Thursday morning. “I used it today and it worked pretty good, so I’m anxious to take it into a game.”

I don’t know how pitching works, really. Not in any in-depth way. Pitchers do. Pitching coaches do. Guys that study hard-core pitching analytics and mechanics do. But most of the rest of us are just making observations that are pretty shallow to the experts. He throws these pitches, his velocity is whatever, he’s effective/not effective. That kind of thing.

All of that said, I wonder how it is that a guy can pitch 13 years in the bigs and then just, one day, say “I’m going to add a new pitch.” I gather that’s because it’s hard to master a new pitch and that they have enough other things to work on, but at the same time, when they talk about the new pitch they added, it’s always a story like this: teammate or drop-in instructor like Pettitte here showing them the grip, them doing it a bit and then — voila — new pitch. If it’s that easy, why don’t pitchers all have a crap-ton of pitches? If it’s not, why is it always reported this way?

My guess: if we went back and looked at all the “So-and-so adds a new pitch” stories for the past decade, we’d find that the new pitch wasn’t really added. That, while it may be featured in a spring game or three, it rarely if ever shows up in their regular season repertoire. That it’s a fancier version of a BSOHL story at the least, a head-game thing for opposing hitters at the most.

But if guys really do just learn new pitches like this and work them in more often than I suspect, man, why aren’t all the pitchers adding cutters and changeups and eephus pitches all the time?