The evolution of Carlos Martinez, starting pitcher

After having his original free agent contract with the Boston Red Sox voided in March 2009 due to a last name discrepancy, the St. Louis Cardinals wasted no time in signing the 18-year-old Carlos Martinez as soon as he was declared eligible by the commissioner's office of Major League Baseball, agreeing to terms with the native of Puerto Plata on April 20, 2010. Even before his call-up in 2013, Martinez has been considered one of the most exciting members of the organization ever since.

Electric, filthy, devastating, nasty, overpowering. These are just a handful of adjectives used to describe Martinez's repertoire. Yet, "complex" was not always a word you could use when discussing Martinez's repertoire. While Martinez always had the potential to throw four different pitcher, he was primarily a fastball-slider pitcher as a minor league and then as a relief pitcher in the big leagues. More often than not, he we would reach back on his fourseamer in hopes of blowing a hitter away or he would snap a wipeout slider in hopes of making an opponent look silly in the batter's box. Not until he anchored a full-time starting pitcher slot in 2015 did his repertoire realize its full potential.

2013 through 2014 PitchF/x Basics (As a Reliever)

Remember: Regarding horizontal movement in right-handed pitchers, a negative value means arm-side movement, whereas a positive value means glove-side movement.

As discussed in the paragraph above, Martinez always had the ability to throw four different pitches, but in his time as an MLB reliever, it was nearly a coin flip (44.12%) as to whether or not he would throw his fourseamer. No matter how fast a fourseamer may be (and don't get me wrong, an average of 98.17 MPH is plenty fast), a big-league hitter will eventually time it up, as shown by pitch-by-pitch results data from 2013 through 2014. In order to make a successful transition to the rotation, some repertoire adjustments had to be made, and as you will see in the table below, Martinez was already ahead of the matter.

2015 to Present PitchF/x Basics (As a Starter)

Remember: Regarding horizontal movement in right-handed pitchers, a negative value means arm-side movement, whereas a positive value means glove-side movement.

Predictably, Martinez's fourseamer velocity is down slightly (-1.66 MPH), but it still remains in the top five of MLB starting pitchers early on in 2016. As you can see, the biggest difference between Martinez the starter and Martinez the reliever is the fact that he goes to his fourseamer considerably less frequently (a ~27% decrease in usage). In its place evolved a changeup that always had the potential to be great, but not until some minor adjustments (and these adjustments show up in the notable difference in horizontal movements: -5.56 inches versus -8.94 inches) did it become a consistent weapon for the right-hander. Now, the changeup just may be the very best on staff, at least according to the results of the poll question (only 466 votes were cast, thought) included at the end of part three of my "Repertoires in Review" articles over the offseason.

Bottom Line

As a starting pitcher, Martinez possesses the ability to throw four above-average pitches in virtually any count. He can throw all four of them for strikes, but when sequenced correctly, he can get plenty of hitters to chase pitches out of the zone as well (an example can be seen below). When he records a first-pitch strike (something he is doing much more frequently now), he is supremely effective (recording a .221/.268/.293 slash line after an 0-1 count in 2015). For a pitcher with a repertoire as deep as Martinez, complexity is a almost always good thing, especially the third or fourth time through a batting order. Something I would really like to see, but will likely never happen, is a completely even (25% times four) split of his pitch frequency. At 25% usage for each, a hitter could potentially face four completely different pitches in one plate appearance. That simply is not fair.

Obligatory Martinez Changeup GIF

As always, credit to BrooksBaseball.net for the PitchF/x data used in this post and PitcherList.com for the GIF.