Jake Arrieta Bounced Way Back Yesterday, and Adjusted as the Game Went On

Two days, two posts identifying and complimenting a huge bounce back performance from a Cubs starting pitcher against a great team on the road. First, it was Zach Davies, who made his second best start since the beginning of the 2018 season. And today, it’s Jake Arrieta, who was excellent yesterday against the San Diego Padres: 5.0 IP, 4H, 1ER, 1BB, 6Ks.

By game score (61), that was Arrieta’s third best start of the season and 18th best start leaving the Cubs after 2017.

Another way to put this performance in perspective using Game Score is that it came immediately after Arrieta’s WORST start since leaving the Cubs (2.0 IP, 6ER against the Giants … which amounts to a Game Score of 5) and his 8th worst start since leaving the Cubs (3.2 IP, 5R, 2ER, against the Reds … which amounts to a game score of 22).

His awful start in Cincinnati was explained by a cut on his thumb, and he was apparently pitching sick in San Francisco … but I’d forgive anyone for feeling anxious, despite those forgiving explanations, given his general career trajectory before this season. But, hey, Arrieta came back out yesterday with the thumb healed up and whatever illness with which he was dealing out of the way and really performed at a high level against a very tough team.

Here’s some thoughts from Manager David Ross after the game (via NBC Sports Chicago):

I thought Jake was really good today. I thought he attacked the strike zone. It looked like the ball had real bite to the finish underneath the zone. A lot of strikes ….

I thought he did great. Big performance. You know, you don’t know how it’s gonna be with that much layoff, and how he only gave us two innings but a lot of pitches and dealing with the sickness, you never know how his (next) start’s going to go. I thought he really had the game under control there and gave us a nice start….

So what was working for Jake yesterday? Well, for one, he changed his pitch-mix quite a bit, relying more heavily on his slider than in any other start this year:

On top of that, he was also throwing his sinker (91.7 MPH), slider (88.7 MPH), and curveball (82.0 MPH) harder on average than he has in any other single start this season. All of which helped him obtain a 30% swing rate on pitches out of the zone (24.8% for the season before yesterday) and a 57.5% swing rate on pitches in the zone (63.2% for the season before yesterday).

In other words, the Padres were guessing far more than usual. And why was that?

Well, although Arrieta didn’t net too many whiffs yesterday, he did start off 75% of plate appearances with a first pitch strike, which is WELL above his average of 54.9% before yesterday. That sort of start puts the batter behind early and into protect mode sooner, leading to more swings on non-strikes, fewer walks, and more strikeouts. This isn’t exactly rocket-science here – everyone knows an 0-1 count is better for the pitcher than 1-0 – but it’s good to see Arrieta executing nonetheless.

I don’t know that we can count on him having that extra couple of clicks on his fastball every time out, but that’s not actually the takeaway here. For me, it’s about watching a veteran adjust, in-game. For example, seeing that he didn’t use his curveball nearly as often yesterday, because the velocity was there. The key isn’t going to be always leaning away from the curveball, but rather knowing when to break it out depending on what else is going on (with the matchup, his body, his velocity, etc.). Using more and more of the changeup when he felt how well it was working. Trusting the slider more because it had great movement. And so on. We saw Jon Lester succeed this way well into his thirties and the Cubs were always hoping Arrieta could do something similar.

In any case, let’s take this one start at a time and hope Arrieta (and Davies) can go on a nice little run here right when the competition gets especially tough. It’s exactly what the Cubs need.