Carlos Martinez makes a changeup adjustment

Way back on August 1st, I wrote my very first piece at VEB (Carlos Martinez is still experimenting). I looked at his success, or lack thereof, against left-handed hitters and his different locations on the rubber, which affected his release points. However, I did this with only the context of his slider. Today, ahead of his start against the Chicago Cubs, I want to examine his changeup.

With more data than we had six weeks ago, we should be able to judge both the effectiveness of the pitch and what adjustments, if any, Martinez has made since then.

In August and the first half of September, the Cardinals are 5-3 when Martinez takes the mound. Over that span, the ace (It’s not Adam Wainwright, Mike Matheny) struck out 56 in 52.3 innings. He also threw a gem—a complete game shutout—last week against the Padres.

What has been the most important tool in Martinez’s repertoire during this stretch has been the changeup. Hitters are batting just .152 against the pitch and righties are managing a number of just .071 (BrooksBaseball).

Much of this is due to location.

BaseballSavant

This is the heatmap for the changeup since August 1st. To lefties, this is a down and away pitch, to righties, low and in. It is not hard to imagine this pitch generating ground balls. But upon further inspection, while the groundball rate is 71% when the ball is hit in play, per BrooksBaseball, a ball is hit in play on just 14.3% of Martinez’s changeups. The changeup is actually a big swing and miss pitch, with hitters whiffing almost a quarter of the time they see it.

For the portion of the season before August, Martinez threw his changeup 16% of the time. Since then, there has been a slight uptick in the frequency as it now sits at almost 19%, per BaseballSavant. This isn't a huge difference, but it is nice to see Martinez recognizing the substantial weapon that he has, and using it more often as well.

It looks like part of the recent success of this pitch has come from tightening up his release point. Here is the release point chart on Martinez’s changeup from April through the end of July.

BaseballSavant

And for comparison, here is the same chart for the period from August 1st to today.

BaseballSavant

As you can see, Martinez no longer releases the ball further than two feet to his arm-side (the third base side) of the rubber. This has allowed him to clip the inside corner to righties and paint the outer edge when facing lefties. Both his ground ball rate and his whiff rate have increased on the pitch during this time.

Whether or not you believe Carlos Martinez is an ace, he is the pitcher most reasonable fans would want leading this team down the stretch. After taking a peek at the remaining schedule, the Cardinals are in a fortunate position. With 16 games remaining, Martinez is penciled in to start 4 of them: today’s game against the Cubs, the series finale in Cincinnati next week, another game against the Cubs, and the series finale vs. Milwaukee.

Of course, the schedule might very well change, especially with Adam Wainwright rumored to be close to returning. It is awkward (but true) to say that many fans aren't looking forward to his return. The pitching staff has done extremely well in his absence and the 36 year old hasn't done much to instill confidence in the minds of fans.

The pitcher who has given fans a reason to believe, is toeing the rubber today against the Cubs. And he is doing so with an elite changeup.