I don’t know if you paid much attention to Rick Porcello last year, but I bet you have made a bad pancake. You know, one of those pancakes when you wait too long before you flip it. Or maybe you tried to make a pancake without preheating the cooking surface. The parallels work as well as any parallels do — you mess things up from the start, despite the best of intentions, but then you are still able to flip the pancake, and you don’t repeat the mistake the second time. So the second half of the cooking process beats the hell out of the first, and in the end, even a messed-up pancake is still a decent enough pancake. And you feel like the next pancake is going to be a lot better.

Porcello got things turned around after it was too late for the Red Sox to get things turned around. So the progress happened quietly, as matters involving the Red Sox go, but if you want an explanation you can just browse to the top of Porcello’s FanGraphs player page. As I write this, there’s a quote from a few days ago, where Porcello talks about how he went back to going sinker-first. The four-seamers up were a neat idea, but the experiment failed, and Porcello found himself when he went back to pitching like himself. It all makes sense, and it bodes well enough for 2016.

So looking ahead, for Porcello, there’s going to be a lot of attention on his sinker. It’s a nice pitch, but I prefer to think about something else that’s gone on in plain sight. When you think Rick Porcello, you don’t usually think curveball. But over the course of last season, he did something suspicious.

Porcello has thrown a curve his whole career, but it didn’t become a regular part of his arsenal until 2013. At that point, he threw a curve every six pitches or so, and he started to generate more strikeouts. He threw about the same rate of curves in 2014, and once more he threw about the same rate of curves in 2015. It’s been a fairly important pitch for him, even if it isn’t a pitch that’s gotten him noticed.

Now for the part that won’t do anyone any good. Below, four Rick Porcello curveballs — one from 2013, one from 2014, one from early in 2015, and one from later in 2015. See if you can spot any differences. Don’t worry if you can’t because this is why we have numbers.

2013

2014

Early 2015

Later 2015

If you’re sharp, you might’ve noticed a drop in velocity. All right, good. But changes in movement? No, you can’t really see that with the naked eye. Not when you’re talking about a matter of a few inches, but thankfully PITCHf/x makes this all so much easier. And with Porcello, something has happened with his curveball over time. It hasn’t just happened without intent, and, oh, this marks the return of me using my pitch-comp system, just for fun.

When you think Adam Wainwright, you definitely think curveball. You probably also think cutter, but the curveball is outstanding, and I’m not going to bother to cite the numbers — just trust me when I say the numbers support the position that Wainwright has had maybe the best curveball in the game. It’s arguably his signature, and thanks to PITCHf/x, we know some things. Covering the whole PITCHf/x era, drawing from Brooks Baseball, Wainwright’s curve has averaged 74.9 miles per hour. Its horizontal-movement reading is 9.0 inches, and its vertical-movement reading is -9.0 inches. Lastly, there’s been a 16 – 17 mile-per-hour gap between the curve and the fastball. This is the Wainwright curveball, as tracked by cameras.

Making use of the Baseball Prospectus PITCHf/x leaderboards, I ran some pitch-comp calculations. For those who don’t remember, this is a method to compare individual pitch types by velocity and movement. The method ends up with a comp rating, and the closer to zero the rating is, the more similar are the two pitches being compared. Now, I ran pitch comps for all 2015 curveballs against the Wainwright curve, but my focus is on Porcello, so what you see in the table are four pitches. You see Porcello’s 2013 curveball, his 2014 curveball, his early-2015 curveball, and his later-2015 curveball. You can see the trend for yourself.

Porcello Curve vs. Wainwright Curve Season Split Velocity Horizontal Vertical Comp Rating FA Speed Gap 2013 Overall 78.9 6.5 -5.5 3.7 13.3 2014 Overall 78.1 7.4 -5.9 2.8 13.2 2015 Pre-ASB 76.6 7.8 -8.2 1.3 15.5 2015 Post-ASB 74.6 7.7 -9.3 0.8 16.8 SOURCE: Baseball Prospectus

Between 2013 and 2014, Porcello slowed his curve a little bit, although it didn’t make a big difference. Early in 2015, Porcello slowed his curve more, and he gave it some extra vertical break. Finally, toward the end of 2015, Porcello took even more off his curve, giving it even more vertical break. The comp score puts him very close to Wainwright, given that the average 2015 curveball comp score is 4.6. And also, there’s the last column, where you see a widening gap between Porcello’s curveball and heater. The most recent gap is almost a dead match for Wainwright’s.

As Rick Porcello closed out 2015, he was throwing a version of Adam Wainwright’s curveball. The pitch is very similar by its basic characteristics, and it’s also very similar based on the difference between itself and the fastball. I’d be shocked if Porcello had Wainwright specifically in mind, because that would be weird, but I presume Porcello has been doing whatever this is on purpose. Where he’s gotten to is pretty fun.

Wainwright’s a righty who stands 6’7. Porcello’s a righty who stands a comparable 6’5, and Wainwright had his ace breakout at 27. Porcello just turned 27 at the end of December. Wainwright’s emergence was fueled by breaking balls, and now Porcello is in an interesting place, where everyone’s thinking about his sinker, but the curveball might be a real weapon. There are similarities. There are very basic similarities, and there are very specific similarities.

Granted, there are similarities between lots of great players and lots of inferior players. The limitation of the pitch-comp system is it says nothing about consistency, and I can’t imagine Porcello yet trusts his curve the way that Wainwright has trusted his. One still has to assume Wainwright commands the pitch better, and then there’s also the matter of Wainwright having the cutter, which is better than Porcello’s. The effectiveness of a pitch is in part about the effectiveness of the other pitches, so Porcello still has a lot of proving to do. The point isn’t that Rick Porcello turned into Adam Wainwright when nobody noticed.

The point is simply that Rick Porcello’s curveball has evolved into something extremely similar to Adam Wainwright’s curveball. You can choose how much to make of that. If nothing else, it’s something to watch for.