Is Carlos Martinez Back to Being Good? He's Definitely Different!

Early in baseball seasons that last 162 games (in a good year), articles such as this one should always come with one caveat. The caveat of which I speak is the ever present early season one called "SMALL SAMPLE SIZE." This is a cautionary tale in just three simple words that hopefully allows readers to mentally adjust to the article by adding their own phrases after some of the stuff written; adding phrases like "if this continues" or "so far this season" or many others that you could come up with at a moment's notice in your own head.

So far in this 2021 season, the St. Louis Cardinals have found themselves watching a Carlos Martinez who seems to be gaining confidence, not only in himself but also in his defenders around him, and is getting results in a way that makes them quite happy they kept with him as a pitcher on this club for more reasons than just "getting value out of the contract already on the books."

Thus far in 2021, Carlos Martinez has made 6 starts, which is tied for the league lead. He also has a league-leading 4 losses, but to pin that on him is a bit unjust I would say. Carlos has pitched to a 3.72 ERA and a 3.80 FIP - which is better than team average at starting pitcher and is also better than league average at starting pitcher. He also has a 1.018 WHIP, stemming from an uncharacteristically low 6.1% BB rate - and thus only 2.2 walks per 9 innings pitched. Not only that, but Carlos Martinez has gone an average of just over 6 innings a start in this young season.

Now let's take a closer look at a few of those starts to see why I believe he seems to be gaining confidence in both himself and his defense around him.

Through Carlos Martinez's first 3 starts of the season, he had:

  • 3 GS

  • 15 IP

  • 5 IP/GS

  • 0-3 record

  • 7.80 ERA

  • .274/.338/.435/.774 line (avg/obp/slg/ops) against him

  • 5 xbh allowed (2 doubles, 1 triple, 2 homers)

  • 2 hit batsmen

Through Carlos Martinez's most recent 3 starts of the season, he has:

  • 3 GS

  • 21 1/3 IP

  • 7+ IP/GS

  • 2-1 record

  • 0.84 ERA

  • .153/.225/.222/.447 line against him

  • 5 xbh allowed (all doubles)

  • 2 hit batsmen

Through the first set of games, he was striking out 6 per 9 innings - which was already quite low for him. That has lowered even further through the second set of games above to just 4.22 strikeouts per 9 innings. He is allowing his defense to shine for him. Then on his April 27th start, when pulled from the game in the middle of an inning, Carlos thanked his infielders prior to leaving the game and saluting the crowd for their standing ovation. (see below AND see cover art by Nicholas Childress)

I feel like this is a different side of Carlos Martinez that maybe we hadn't seen before - and it's definitely a different pitcher than we've seen before.


Entering the 2021 season, Carlos Martinez's previous career high for percent of pitches inside the strike zone was sitting at 52.5% back in 2017 - when he was a fairly dominant starter. It got as low as 43.8% last year but was fairly consistently at a 50-50 breaking point. Take a look at this line graph of the 2015-2021 seasons and see where it's at now: 56.2%.

This is allowing Carlos Martinez to throw first pitch strikes over 68% of the time this year. His career average is just under 62% and league average is closer to 60.5% in his time pitching. He's getting many more swings and significantly less whiffs on his pitches and he's also allowing a higher percentage of contact in the zone. (What players are doing with the quality of that contact is for another article.)

Carlos Martinez is working with a different repertoire than he did when he was a strikeout/groundball extraordinaire in 2015-2018 (prior to his injury). What I mean by that is his pitches do not act exactly as before. He is working with the least velocity on his pitches that he ever has. He's working with more horizontal movement on his pitches than he ever has as well.

As a starter, between 2015-2018, Carlos Martinez threw:

  • his 4-seam fastball 26% of the time at 96.4 mph with a 2,115 rpm spin rate,

  • his 2-seam/sinker 26.1% of the time at 94.9 mph with a 2,016 rpm spin rate,

  • his cutter 2.5% of he time at 90.4 mph with a 2,304 rpm spin rate (keep an eye on this one),

  • his slider 10.7% of the time at 84.7 mph with a 2,173 rpm spin rate (and this one),

  • his curve ball 13.7% of the time at 85.1 mph with a 2,034 rpm spin rate, and

  • his change up 16.6% of the time at 87.5 mph with a 1,982 rpm spin rate.

This year, here is what Martinez is working with thus far:

  • a 4-seam fastball 25% of the time at 93.8 mph with a 2,091 rpm spin rate,

  • a 2-seam/sinker 12.2% of the time at 91.6 mph with a 1,981 rpm spin rate,

  • a cutter 25.1% of the time at 90.9 mph with a 2,209 rpm spin rate,

  • a slider 23.8% of the time at 83.0 mph with a 2,106 rpm spin rate,

  • a curve ball 2.9% of the time at 79.3 mph with a 2,050 rpm spin rate, and

  • a change up 11% of the time at 85.0 mph with a 1,892 rpm spin rate.

As you can see above, Martinez has lost about 2-3 mph on basically every pitch in his repertoire from the last time he was a starter. His K% was over 23% in the time frame above and his ground ball rate was over 53%. That means 3/4 of the time, Martinez was getting worm killers or strike threes. This year he's only getting ground balls about 48% of the time and is striking out 13.5% of batters faced. That puts the combined percentage just over 60%. He's allowing about 3 more out of every 20 batters to put the ball in play and let his defense take care of it.


Let's circle back to the movement on his pitches being a bit different. I'm going to borrow a bit from Matt Graves over at Redbird Rants, who took a great look into some new data over at Baseball Savant on something being described as "seam shifted wake" or SSW.

His thoughts are based on images like this one below, which I will try my best to explain to you, but really you should go ahead and read his article because it's incredibly well thought out.

Let's talk about the two charts above. These images above only talk about the movement on the ball caused by the spin of the pitch. It doesn't take into account gravity, wind, etc. - any other force on the ball. Only the spin based movement of the pitch.

Let's focus on the slider first, in yellow.

The yellow on the left describes Martinez's slider based on the spin out of his hand - what the HawkEye camera system sees as the ball is released. My guess is that would be what the movement the hitter would expect to see based on the spin of the ball coming out of Martinez's hand. However, the way the ball is spinning can be counteracted a bit by where the seams on the ball are located at the release. That counteracting needs to be accounted for by looking at...

The yellow on the right, which is the observed movement as the ball comes to the plate (how much it actually moved from release point to the plate) is what the spin on the ball did to the pitch in actuality. In this case, my guess is that the slider has not dropped as much as the hitters might have thought this season. That difference between what the hitter sees out of the hand (the left graph) and the observed movement of the pitch (the right graph) from the release point to the plate is what is called seam shifted wake (SSW). So SSW is potentially what makes what hitters thought a pitch should have done NOT do that and instead break differently, thus making a hitter look impotent at the plate.

On a side note, if you looked at the differences of the graphs differently it might seem like it implies that the ball ROSE UPWARDS on his slider. It did not. It simply did not drop as much as originally thought. The movement on that was more horizontal.

If we look at his cutter in brown, since he's throwing it ten times as often as he used to do as a starter, you can see that the ball cuts more to the left (away from a right-handed batter or towards a left-handed batter) than the spin out of his hand might suggest to a batter. Again, that implies to me more horizontal movement than might be expected.

You can also see that his sinker in orange and his change up in green have probably the MOST significant movement based on seam shifted wake alone. They both sink more and drift in more to right-handed hitters (and away from left-handed hitters) due to their spin than other pitches seem to move based on this alone.

Lastly, pitches that are located directly across the clock face / circle from each other in the images above are said to "mirror" each other. That is, the spin of those pitches looks the same initially to the batter because they are exact opposites of one another. Here's a good picture of this from Mike Petriello of of Shane Bieber's four-seam fastball and curve ball and what that would look like to a hitter.

If we look back at what Carlos' chart looks like above, we can see that he has mirrored both his sinker and change up quite well with his slider - likely making them difficult to distinguish out of the hand. Which of the three is it? Is it going to be 92 with sink? Is it going to be 85 with sink? Is it going to be 83 with a sweeping motion? WHO KNOWS?!?


Let's check in (courtesy of Nicholas Childress) on Carlos' repertoire in 2021 - or at least the four pitches above that seem to do best with seam shifted wake and pitch mirroring.

Going clockwise, starting in the top left:

  1. A green tailed sinker

  2. A yellow tailed slider

  3. An orange tailed cutter

  4. A blue tailed change up

I think you can tell the horizontal movement incredibly well on the yellow slider (goodness, I love that camera angle). I think the orange cutter is the hardest for me to see, personally. The downward and rightward tilt on the green sinker and blue change up is quite prevalent to me, despite the terrible camera angle on it.


To recap, what we're seeing this year - especially as of late - is a Carlos Martinez that is quite effective at getting outs. That's what pitchers are paid to do. Get outs. Martinez is as effective at getting outs lately as he was when he was at the top of his game, but his outs are coming in a much different manner. Because Carlos' outs are coming in a much different manner, we can look and see that his pitches - his "stuff" - isn't nearly as dominating on the velocity and spin side as what they once were so he has turned to different types of movement on his pitches than before (a tilt towards horizontal) to try to "trick" hitters instead of just challenging him with his best "stuff." Interestingly enough, though, he's challenging them by putting a higher percentage of pitches in the zone where hitters should be teeing off on it, but because we have an elite defense with everyone back healthy, he can rely on them a bit more - and has done so very much to his advantage.

I think this is just a fascinating transition from Carlos - who many believe to be on the mentally weak side - to take the very Cardinals-esque approach of "zigging when others are zagging." For Carlos here, that takes the form of pitching to contact while others are looking to rack up the strikeouts. For me, this is going to be fun to follow moving forward. Does he continue to rely on cutter/slider and the small differences between those two? Does he continue to attack the zone and rely on his defense?