When James Paxton made his first start of the season on July 25 in Washington, it was immediately apparent that something was wrong with the lefty. The velocity on his fastball was way down. His delivery was visibly wrong, even to the untrained eye. And, of course, he got absolutely shelled by Washington and in his subsequent start against Boston.

It was and is fair to be concerned about Big Maple. He just hasn’t look right, especially before yesterday. Now, with the caveat that this was just one game, yesterday was a step in the right direction for Paxton. There is work for him yet to do, but I think there were some positive signs in the underlying data.

Let’s start with the fastball. Paxton’s fastball was the source of the majority of his struggles in 2020. We all saw it manifest clearly with his velocity, which is way down:

That drop is the largest such drop in baseball year-over-year, which is not great. There was also a corresponding drop in spin-rate that was especially visible before yesterday’s start:

As they say, that is not what you want. It all led to some pretty brutal indicators against the pitch. Here is the game-by-game data entering yesterday’s start:

  • July 25 (@ WAS): 22 FB, 16 swings, 3 whiffs (19%)
  • August 2 (BOS): 34 FB, 21 swings, 3 whiffs (14%)
  • Total: 56 FB, 37 swings, 6 whiffs (16%)

This is all pretty straightforward: the fastball was slower and it had less “late life” (spin). It’s no surprise that they were sitting on it, but it’s still really alarming to see a 66% swing rate on the pitch with a swing-and-miss rate as low as 16% on those swings. To boot, the other 84% ended with some very, very loud contact, with an average exit velocity of 93 mph. The pitch was not fooling anyone and batters were teeing off on it. This was not a CC Sabathia soft contact situation.

However, where this was all obvious cause for concern, yesterday’s start provided some cause for cautious optimism. Let’s start with the velocity, which jumped up a bit. In fact, 4 of Paxton’s 5 hardest thrown pitches came yesterday and he touched 94 miles-per-hour twice. To wit:

And:

It’s still not the 100 mph he touched last year, but progress is progress, right? I’ll take what I can get so far. To be fair, his average velocity yesterday was 92.3, which is about the same as his first start. But fastball life isn’t just about velocity. It’s also about spin rate, and that’s where yesterday’s start was most encouraging. Look at the nice bump here:

The scale here makes it seem more dramatic than it is, but this is significant nonetheless. His average fastball RPM of 2246 yesterday tracks pretty closely to his 2019 average of 2263. The recovered spin rate gives his fastball much more life and results in swings like this:

So, while the velocity may not be all the way back, increased life on the fastball can help compensate a bit for that drop. It’s why his fastball whiff-per-swing rate jumped to 28% yesterday. In fact, it was quite a bit higher before the disastrous 7th inning, which I am officially chalking up to Paxton running out of gas around 80 pitches or so. Given his struggles, he hadn’t thrown this many pitches in a game since Game 5 of the ALCS in October.

Finally, Paxton’s release point is still all over the place. I’m not sure if this is worth being concerned about. It’s up from the first start and it could be the result of some actual tinkering. Here is his vertical release point on a game-by-game basis in 2020:

And here it is on a game-by-game basis since the start of 2019, which doesn’t have the same game-by-game variance:

Something is still off here, but it’s good to see it on an upward trend, at least, and it’s certainly closer to 2019 than it was in his first start back. A three-game sample is obviously not big enough to draw any conclusions, but it’s interesting nonetheless. We’ll have to keep an eye out on this.


One start does not signal a complete recovery, and there are still plenty of warning signs for Paxton. His velocity is still down, his release point is obviously still in flux, and the start itself came crashing down in the 7th inning. Regardless, there was plenty to indicate that yesterday’s start was the first step in Paxton’s recovery. The next step will be for Paxton to build on that success and re-establish himself as a top-of -the-rotation talent.