Carlos Martinez just keeps getting better

Carlos Martinez is short for a pitcher. Ostensibly, that makes it difficult for him to throw with great downhill plane. Hitters probably see the ball a little bit better coming out of his hand than if he were, say, 6’5.

Outside of that, however, it’s difficult to pinpoint what, if anything, Martinez lacks relative to his peers. Elite velocity? Check. A proven ability to garner swing-and-misses? You bet. How about an outstanding ground ball rate? He’s got that too.

So when you talk about the best pitchers in the National League, Martinez has to be included in that discussion. He shouldn’t be one of the first names you throw out there — that’s still reserved for the Kershaws, Syndergaards and Scherzers of the world — but he should be one of those “What about Player X?” guys that makes your friends nod and say, “Yeah, that guy is really damn good.”

What’s really amazing, however, is how quickly he’s evolved into that type of player. It was just a few years ago that he was mostly a reliever. A decent reliever, sure, and one who had come up through the minors as a notable starting pitcher prospect, but not like “Holy crap, why isn’t this guy in the rotation” good. As recently as 2014, it looked more likely that Cardinals manager Mike Matheny would grind him into dust than Martinez would ultimately solidify a spot in St. Louis’ rotation, let alone at the top of it.

And yet, from almost the moment he finally got that rotation spot locked in, Martinez has been excellent. After his pitch usage varied wildly as a reliever, he’s settled in with one of the most diverse and effective repertoires in the majors:

For a lot of pitchers, that many pitches can lead to some diminishing returns. Some guys are so focused on expanding their selection that they fail to maximize their best pitches at the expense of improving their worst.

That’s not really the case for Martinez. All four of his pitches are effective; his fastball, sinker, slider and changeup all had positive linear weighted values in 2016, and Martinez has shown a willingness to throw each of those pitches in a variety of counts.

When your fastball sits in the mid- to upper-90s, your slider earns a whiff on nearly 40 percent of swings, and your changeup looks like this...

...how is a hitter supposed to be able to cope with the fact that any of those pitches can be thrown at any point in an at-bat? And that’s without even mentioning his two-seamer, another quality pitch.

It appears, however, that Martinez is quite satisfied with “just” four quality offerings. During the last few months of 2016, he began toying with a more traditional curveball to supplement the slider. Over the offseason, he talked about wanting to continue to work on the pitch to further deepen his arsenal, and he followed that up by throwing a handful of curves as he dominated the best lineup in baseball on Opening Night.

Adding yet another pitch could, as I mentioned earlier, lead to some diminishing returns. It’s certainly too early and the sample size too small for us to make a definitive determination on whether the curveball is good or not, but if not then Martinez would be wise to scrap it sooner rather than later. And if it is yet another good pitch? Well, then I guess Martinez will become even better and even more unpredictable.

And as great as it is that Martinez’s continually expanding selection can keep hitters off balance and garner swings and misses, it’s also important that a pitcher be able to limit quality contact, at least to the extent to which he can control such a thing. And surprise, surprise, Martinez has become great at that as well.

That’s because he’s one of the premier ground ball instigators in baseball. From the beginning of 2015 to now, only former Cy Young winner Dallas Keuchel and former Cardinal teammate Jaime Garcia have had a higher ground ball rate than Martinez’s 55.3 percent.

Martinez is not without flaws, of course. Just about every pitcher to ever step on a mound had a weakness or two. His walk rate is fine, but if he is really going to enter Cy Young discussions, that will probably need to improve a bit. He might miss fewer bats than his stuff would indicate. But even those flaws, if you can even call them that, seem like nit-picking. Not everyone has to become a superstar.

Still, Martinez is damn close already, and seemingly gets closer every year. Not bad for a guy who some were pegging as a reliever just a few years ago.