How Blake Snell got his groove back against the Diamondbacks

Blake Snell put together his best start of 2019 in Monday night’s game against the Arizona Diamondbacks, taking a perfect game into the sixth inning. He was coming off his worst start of the year last week in Kansas City.

Taking a look at his final lines for each game, it’s hard to imagine they were both the same pitcher.

So what changed?

Unlike his start against the Rockies in where he changed his pitch mix and sequencing, his successful mix against the Diamondbacks was largely the same as his poor start against the Royals.

The difference was his ability to locate.

First let’s look at his chart against the Royals from last week:

To compare, here is the same chart for Monday night’s game:

In his first start back from the IL, Snell just wasn’t able to find any type of consistency in commanding his pitches. But rather than making too many adjustments, Snell and catcher Mike Zunino stuck to a similar game plan.

As a result, he showed much more precision across the board, giving Arizona a steady diet of fastballs glove side up, curveballs glove side down, and changeups armside down.

Here is what Zunino told Josh Tolentino of the Athletic:

Quite honestly that first inning. That first inning when he came out locating. He mixed everything ... He executed his pitches.

(You can see the full story here)

Snell was able to locate his pitches properly, and was able to tunnel—or make all of his pitches look exactly the same until they break, also known as the tunnel point.

Here it is in action. first, with the fastball up in the zone and the curveball below the zone:

Here is the flight path of each pitch of that at bat using Baseball Prospectus’ Interactive Matchup Tool

Effective tunneling keeps the hitter from tracking the baseball out of the pitcher’s hand. If every pitch looks exactly the same, it becomes next to impossible to sit on any one offering. For the pitcher, it allows him to have a repeatable delivery, giving him both the ability and confidence to throw any pitch on any count.

For Snell, it allowed him to get more swings and misses this time out:

Pitch tunneling isn’t something Snell is necessarily known for, but after seeing what he did against Arizona, it’s clearly something that works for him. It will be interesting to see if (and how) he continues to rely on this strategy moving forward.