Did the Cardinals unlock Jordan Montgomery?

One of the iffiest feeling trade deadline deals in recent Yankees history is quickly feeling worse every time Jordan Montgomery takes the mound for the St. Louis Cardinals. He’s been dominant in his four starts since moving teams, culminating in Monday night’s complete-game, one-hit shutout against the Chicago Cubs — the first nine-inning effort of his career. He has allowed only one earned with his new team so far.

Suffice it to say that this is not the Monty we recognize, who was highly dependable but never a true shutdown starter. While we only have a limited sample size, it does appear that Monty may have altered his pitching approach in St. Louis, as many starters will do upon moving to a new pitching coach and a team with different sensibilities in general.

Of note, in his four starts with St. Louis he’s almost completely changed up his usage of his sinker vs. his four-seam fastball. Every month of the season through July he increased the usage of his sinker, until in July it was 49 percent of the pitches he threw. Meanwhile, his four-seam fastball had almost vanished with the Yankees — he threw it less and less as the season went on, to the point where we only saw it 4.8 percent of the time in July.

With the Cardinals, he’s thrown the sinker 30.2 percent of the time, and his fastball 30 percent.

Note: Montgomery’s last start with the Yankees was July 31, so August numbers only contain Cardinals starts.

The last times Monty’s sinker and fastball usage were close to even was in his first two seasons, 2017 and 2018. Clearly, the Yankees (or Monty himself) made the decision to move him away from the fastball.

The Athletic reported after his shutout that Cards catcher Yadier Molina specifically wanted Monty to increase the use of his fastball, and Monty concurred because of the pitch’s mixture of velocity and his ability to place it at the edge of the plate.

It does have logic behind it — hitters have just a tick lower of a hard hit percentage off the fastball than his sinker. And his fastball has always been a better strikeout pitch, as FanGraphs noted not terribly long ago. There, they attribute better pitching by him from the turn from the fastball to the sinker, and noted how that pitch has worked wonders for the likes of Clay Holmes. Of course, Holmes’ performance this year shows us that a powerful sinker can’t solve every problem. And Monty had a particularly difficult run from late June through his trade.

Is this new pitch mix the key to Monty’s amazing run in the National League so far? The Cubs rank ninth in the NL in OPS and eighth in home runs — they are not exactly the hardest team to shut down. His first start there was also against the mid-meltdown Yankees (in case you somehow forgot) who by all accounts were shocked to see their teammate moved.

Monty is obviously not a perpetual 0.35 ERA pitcher, because no one is. There are signs that he’s been just a bit lucky too. He has a 100-percent left on-base rate in 75 percent of his St. Louis starts, which is clearly not possible to sustain. Still, his results so far with the Cardinals — and his confidence — seems to me to suggest that abandoning his fastball with the Yankees was not the way to go. The shine on the sinker is starting to come off a little, I think.