One of the most pleasant surprises to come out of the 2014 season was Jake Arrieta’s meteoric rise to the top of the Chicago Cubs’ rotation. Having had the “stuff” for years, Arrieta was never able to harness his immense skill to the level he did in 2014 (2.53 ERA, 2.26 FIP, 2.73 xFIP, down-the-ballot Cy Young votes).
Although there was likely a confluence of events contributing to Arrieta’s breakout, perhaps the one we’ve heard the most is is the increased use and effectiveness of his slutter (what we’ve colloquially been calling his slider/cutter combination – think of it as a hard, shorter-breaking slider … or a cutter with a ton more movement than you’d expect). Just last week, Eno Sarris took a deeper dive into Arrieta’s slider, to examine what made it so effective and what was different from years past.
Through a collection of charts, graphs (which you can play around with) and quotes from the man himself, Sarris identifies that Arrieta was doing more than simply using his slutter more often – a conclusion I was relieved to discover for both injury and future success reasons.
Effectively, Arrieta is able to manipulate the speed and trajectory of his slutter quite frequently – so much so that it can appear as three distinct pitches. More importantly, Arrieta is using each specifically for key strategic situations. For example, Arrieta describes using a harder, elevated slutter to lefties (more like a cutter), and using a slower, hard-breaking slutter to righties (more like a slider).
It’s gotta be nice to be able to manipulate an already-nasty pitch like that. Importantly for future projection purposes, Sarris indicates that Arrieta’s been more comfortable manipulating the speed and trajectory of his slutter over the last two years, which is supported by the data in Sarris’s piece (in short: in 2012, unlike 2013 and 2014, there was almost no variability in velocity and very little variability in movement). That comfort has come in large part thanks to much better command of all of his pitches in the last two years (he was surgical with the fastball last year), which puts him in better counts, and allows him to be more aggressive with the slutter.
I strongly urge you to read Sarris’s piece, which really breaks down how Arrieta did the magical things he did with the slutter the last couple years.
Arrieta is going to be a big part of the success or failure of the 2015 Chicago Cubs. So it’s encouraging to receive further evidence that his 2014 breakout wasn’t based on smoke and mirrors. Something as simple as better command of his fastball allowed Arrieta to more effectively use the rest of his arsenal, and that seems like something that is (hopefully) very repeatable going forward.
And, since we’re discussing Arrieta’s nasty pitching ability, we might as well watch some of it. How about the highlights from his late September start against the Cardinals, in which he struck out 10. I count three Ks in this video that came by way of the slutter, with an exceptionally sick example at the 1:12 mark (and a perfect demonstration of his ability to slow down the slutter and give it more lateral movement):