Grimm Reaping Benefits of Experience, Refinement of Repertoire

I really like Justin Grimm. Not only was I really impressed after seeing him interacting with a bunch of young fans at an event the other day, all the while displaying his easy Southern demeanor, but the guy has been lights-out for the Cubs coming out of the bullpen this season. That wasn’t always the case though.

When Grimm came to the Cubs, he was a bit of a tweener, a guy who was being used as a starter but who really didn’t have the stuff to go deep into games. Prior to joining the Cubs in 2013 as part of package for Matt Garza, he had compiled a 6.37 ERA and 1.652 WHIP over 17 starts for the Rangers. He had averaged just over 5 innings per game as a starter, and was allowing 1.5 HR per 9 innings. That’s, uh, not good.

The Cubs’ first order of business was to move Grimmer to the bullpen, where they felt he’d be more effective. The change paid immediate dividends as his ERA dropped to 3.78 and his HR/9 to .52; but the best was yet to come for the lanky right-hander.

Grimm has always been a fastball-first guy, but he was forced to conserve his energy as a starter. That inability to use max effort resulted in a lukewarm heater that averaged only 92 mph over the course of the 2012 and 2013 seasons. Couple that with the attempt to master the type of pitch repertoire necessary to become a viable major league starter and you’ve got a recipe for mediocrity.

Just look at this chart of Grimm’s pitch mix from 2012-14 and see the volatility in his various offerings. Any pitcher’s usage is going to change throughout a season as his feel for given pitches waxes and wanes, but Grimm never seemed able to find a good deal of comfort with anything other than the fastball. There are, however, some emergent trends in 2014 as the fastball and curve appear to be standing out late in the season.


Focusing now on just 2015, we see a lot less variance in pitch usage. At this point, Grimm is turning to only two pitches, which is more common for a short reliever. It should be noted that PITCHf/x credits Grimm with using the curve and slider almost equally, while Brooks clearly classifies his breaking pitch as a curve. Whatever you call it, he’s using it more effectively.


A big key to that effectiveness is the fastball, which has gained a couple ticks since Grimm was moved to the ‘pen full-time. His four-seamer averaged 94 mph in 2014 and is up to 94.7 this season, no small difference from just a couple years ago. He’s throwing the breaking ball a little harder too, but the 12 mph drop from the fastball makes the offspeed stuff that much harder for opposing hitters to deal with.

It’s not just usage and speed that has made the difference though; location has been a major factor. As you can see from the chart below, Grimm was working way too much over the plate from 2012-14. Sure, he loved that lower corner, but the middle of the zone got way too much play.


You don’t even really need to understand what you’re looking at to see that this year’s heat map is significantly different from the one above. It’s clear that Grimm is pounding that low glove-side corner and keeping the ball down and away to righties and low and in to lefties. Working consistently off the plate does mean he’s averaging more BB/9 than at any point in his career, but those numbers are also inflated by a small sample size.


And what’s more, the walks are rendered relatively inconsequential by a 13.50 K/9 rate that blows away anything Grimm has put up in the past (career high 3.15 K/BB). Some might worry that having such a clear plan of attack would allow hitters to adjust, but the best part of working that corner is that hitters can’t really do anything with those pitches even when they know what’s coming.

The heat map below shows the percentage of swings and misses for each section of the hitting zone. Not surprisingly, Grimm’s go-to spot is like a Bermuda Triangle for bats.


As for the point about hitters not being able to do much with pitches in that location, we can see an illustration below. Everyone is going to give up a hit every now and again, but what a short reliever absolutely can’t allow is extra base hits that will either put a man in scoring position or drive home inherited runners. As the heat map clearly shows, Grimm has been cool when it comes to allowing big hits.

But the 2-for-41 total represented by the four squares calls for a more powerful adjective that just “cool.” Hmmm, what’s cooler than being cool? Ice cold!


Yes, ice cold indeed. That’s exactly what Grimm has been to inherited runners; his 88.8% left-on-base percentage is easily the best on the team and ranks 14th in baseball among pitchers with at least 20 innings of work. His 1.69 ERA and 2.52 FIP are the lowest in the Cubs bullpen among pitchers with at least 25 innings, and his 53.6% ground ball rate tops the team as well.

It’s pretty clear that as Grimm continues to settle into his role as a short reliever/setup man, he’s only getting better. And while it’s impossible see into the future, one would imagine the Cubs are going to be very happy with the young man who’s under club control until 2020. Given the uncertainty of the other guys who came over to the Cubs with Grimm in the Garza deal, it’s possible that the converted starter could end up being the best of the bunch.

No need to get ahead of ourselves though, there’s still plenty of baseball to play. But there’s a lot to like about a guy who’s just now coming into his own, both as a pitcher and a representative of his ballclub off the field. It’s something that goes unnoticed in light of all the stats, but part of this whole Cubs rebuild has involved bringing in guys with high character who can actually be productive members of the community.

If given the choice between having a bunch of good citizens or winning a bunch of baseball games, I’m thinking most fans are going to opt for the latter. But with Grimm, they won’t be forced to choose, which means the Cubs will be reaping the benefits of their young reliever for several years to come.

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