Examining GB/FB Splits: Portland Beavers Rotation

If you follow the minor leagues, it’s pretty easy to know a pitcher’s strikeout rate, walk rate, or ERA. One stat, however, that you have to dig a bit deeper to get to is batted-ball splits–groundball rate, flyball rate, and liner rate.

Of course, groundball rate is a great skill for a pitcher to have, and it can (to an extent, at least) transcend low strikeout rates. A pitcher who doesn’t get many swings and misses is a more palatable option if he induces a lot of grounders (a la Chien Ming Wang) rather than inducing a lot of flies (a la *insert AAA mainstay here*).

(If you’re reading this article on the Chicken Friars homepage, click “Continue Reading” for the rest of the entry).

With that in mind, let’s take a look at the Portland rotation (currently Josh Geer, Will Inman, Cesar Carrillo, and Radhames Liz)* and see how their batted-ball splits stack up.

*No, they don’t have a four-man rotation, but there’s no clearly-defined fifth starter. Currently it’s a rehabbing Sean Gallagher. Nate Culp made a couple of starts and was sent back to Double-A, and Matt Buschmann has a spot-start as well.

Geer is known as a sinker-slider guy, but his splits in the majors last year (42.4 GB% and a horrific 2.37 HR/9) didn’t back that up.

In Portland this year, Geer’s got the groundball rate up to 49.6%, which is above-average but not fantastic. It does make his K rate (5.36 K/9) a bit easier to take, particularly in conjunction with a very low walk rate (1.56 BB/9). However, he’s allowed as many homers (7) as walks, so despite the increased grounders, the homers are still a major issue, and a big cause of Geer’s 5.82 ERA. He has to solve that to get back to the big leagues.

Inman has more of a flyballing reputation, and he’s lived up to that this year, with a below-average 38.1% groundball rate. Inman’s only allowed two homers all season, however. It’s worth noting that his groundball rate goes up to average against lefties (41.7%) and his popup rate against them (25.9%) is also very high. It’s only righthanders who hit a large portion of outfield flies against him (37.5%, almost double the 19.9% for lefties). On the other hand, Inman’s strikeout rate against righties (8.50 K/9) is more than double his rate to lefties (4.02 K/9), so he becomes a strikeout/outfield fly pitcher to righties and grounder/popup pitcher to lefties, it seems.

These numbers help explain why Inman’s homer rate is so low despite his poor overall grounder rate.

Carrillo, as I mentioned a few days ago, has a very poor strikeout rate (3.82 K/9) and just a 1/1 K/BB ratio, which makes his 3.13 ERA look…fishy. His FIP is just 4.08, which is worse but still solid, although that’s partially due to Carrillo not allowing a homer all season.

Carrillo has a 51% career groundball rate, but that’s dwindled to a mediocre 40.4% this year. Like Inman, he gets more grounders against lefties (44.4%) than righties (38.4%). He’s not enough of a groundball guy to make that terrible of a strikeout rate look okay, though–he’d need to be over 60% to make up for it, at least.

Liz has a reputation of flying open too early with his release, which leads to his missing up in the zone and getting a ton of flies.

In his MLB career, the hard-throwing Liz has an extremely low 31.7% groundball rate, and has had homer issues because of it (1.63 HR/9).

Liz is striking out 11.88 batters per nine innings in Portland this year, and at that rate, it doesn’t really matter what sort of splits you have. However, he’s made a bit of progress, getting his groundball rate up to 40.3%. He’s been filthy to lefties, with both a 13.91 K/9 and incredible 59.3% groundball rate. This is likely due to Liz’s good sinking changeup, which he uses as his primary offspeed pitch to lefties.

His primary offspeed pitch to righties is an inconsistent breaking ball, which has led to a lower (but still great) 10.29 K/9 and a troublesome 27.5% groundball rate. Not surprisingly, both of Liz’s homers allowed are to righties. He should consider using the changeup more to righties to help that out.