Sinker-slider sequence key for Carlos Martinez versus lefties

Welcome to the final edition of what I hope has been an informative three-post series focused on Carlos Martinez's continued struggles versus left-handed hitters. I published the first post of the series exactly one week ago, recorded and subsequently released a video (tip of the cap to @NChill17's editing skills) on the topic yesterday, and today, I cap it all off with an even more specific approach I hope to see from Martinez going forward.

As you may recall from my first post, I briefly mentioned tunneling and sequencing -- and the role the sinker plays in both. For those who did not choose to read that post (I really wish you had!), here's what I said:

Given their respective velocities, their movement profiles, and what hitters see on their flights to the plate, the changeup and slider do not tunnel or sequence particularly well. Thus, a third pitch -- with a different velocity but similar movement profile (the sinker, in this case) -- must still be available to help set up these two offspeed options.

Alone, there isn't too much to learn from these two sentences. I purposely did not dig into the topic much further because I had today's post in mind from the very beginning. So what exactly do I mean by "what hitters see on their flights to the plate," you ask? It all starts with reddit, actually. Two years ago, a uniquely-named user uploaded an image to /r/Baseball titled "What the batter sees." The two of the pitches in question when discussing Martinez's approach versus lefties? Sinker and slider.

What the batter sees (.gif via @cardinalsgifs)

Of the five pitches included in the reddit upload, the sinker and slider probably look the second most similar. Sure, the curveball and sinker provide an almost identical look, but when you factor in axis tilt, release point, velocity, and initial movement (particularly vertical), the differences between the two are considerably easier to spot.

Of course, the sinker doesn't possess the defined red dot seen in the slider, but given how tightly spun each pitch is, their respective velocities, and the amount of run (arm-side horizontal movement) Martinez can induce on his sinker, I would not be, in the least bit, surprised if the two looks blended together at times for opposing hitters.

Okay, so the two pitches provide somewhat similar looks to opposing hitters, why else should they be sequenced together frequently? I'm glad you were wondering exactly this, honestly. For being two vastly different pitches, the thought process behind their respective effectiveness is actually quite similar -- hard, late movement. Martinez's sinker averaged 95.20 MPH last season as compared to 85.50 MPH for his slider. The sinker averaged 14.29 inches of dragless horizontal movement (arm-side), compared to 8.98 inches (glove-side) for the slider. The average estimated vertical release points varied by barely more than one inch (5.46 feet versus 5.36 feet).

So, what does all this mean? What it means is that we are dealing with two pitches that, in theory, should tunnel and sequence quite well. They should tunnel and sequence well enough to become a viable weapon for success versus lefties for the right-handed throwing Martinez. And if you are still having trouble visualizing the points I'm trying to make (completely understandable!), look no further than the following .gifs from @cardinalsgifs, as they provide an illustrative foundation for my thoughts:

Sinker-slider to Ian Happ (BrooksBaseball At Bat)

Despite a very similar release point and the crossing of paths upwards of halfway to home plate (look at the red-orange part of the trail), these two pitches land in two very different parts of the zone. After taking strike one -- a middle-in 95.8 MPH sinker -- Happ jumps on the third pitch of the plate appearance as if he's being thrown yet another middle-in sinker. Fortunately for the Cardinals, Martinez (and Carson Kelly) had another pitch in mind -- a back-foot 88.2 MPH slider. Frankly, you cannot truly appreciate this two-pitch, back-to-back sequence without seeing the two pitches overlaid, as they are below:

Sinker-slider (overlaid) to Happ

Simply unhittable.

Bottom line

Remember the league-wide numbers I provided in post number one regarding inside sinkers (.308 xwOBA) versus outside sinkers (.373 xwOBA)? Well, the slider yielded similar results as inside sliders posted an xwOBA of .227 versus .275 on outside sliders (courtesy of Over the course of the last week, I wouldn't say I've solved Martinez's struggles versus lefties (again, it's not that easy), but I have certainly provided the 26-year-old with a two-pronged attack -- centered on sequencing inside with two of his top pitches.

As always, credit to the great @cardinalsgifs,,, and for their contributions to this post.