Cahill’s Lack of K’s

As he leaped from rookie ball to the big leagues in a few short seasons, right-hander Trevor Cahill had little problem making opposing hitters whiff.

A California prep product taken in the 2nd round of the 2006 amateur draft, Cahill dominated the competition in A-Ball and Double-A. In 105.1 frames in the Low-A Midwest League in 2007, the 6-3 hurler punched out ten batters per nine innings with 3.42 BB/9. Cahill then took on the High-A California League and AA Texas League in 2008. His combined line? 124.1 IP, 9.8 K/9 and 3.6 BB/9.

Sure, Cahill’s command sometimes abandoned him. But he drew as much praise as any pitching prospect in the game. And why not? In addition to all of those K’s, Cahill was a groundball machine. He burned worms at a 56.4% clip in 2007 and kept the ball on the ground 61.5% of the time in 2008. Generally, strikeouts and groundballs have an inverse relationship: one comes at the expense of the other. It’s rare to find a young pitcher so adept at making batters whiff or chop the ball into the dirt when they do manage to make contact.

Heading into the 2009 season, Baseball America ranked Cahill as the second-best prospect in the Oakland A’s system (Brett Anderson was first). BA complemented Cahill’s two-seam fastball “with outstanding sink and running life, enabling him to rack up both grounders and swinging strikes.” But that was just the tip of the iceberg as far as his repertoire was concerned: Cahill also came equipped with a “nasty 79-81 MPH knuckle curve,” a low-80’s slider and a developing changeup.

Cahill figured to open the ’09 campaign at AAA Sacramento. Instead, the A’s jumped the 21 year-old up to the majors. While his minor league tag-team partner Anderson made a seamless transition (3.61 xFIP in 175.1 IP), Cahill just tried to keep his head above water.

In 178.2 innings pitched, Cahill compiled a 4.92 xFIP. While he racked up the whiffs in the minors, he K’d just 4.53 batters per nine frames, while issuing 3.63 BB/9. Cahill’s punch out rate was 8th-lowest among starters tossing at least 150 frames. He displayed slight groundball tendencies (47.8 GB%), but he didn’t wage a ground assault on hitters, either.

While scouts loved Cahill’s expansive collection of pitches, the young righty nearly abandoned his breaking stuff during his rookie year. Cahill threw both his fastball and sinker around 30 percent of the time, while showing hitters his changeup about 29 percent. That low-80’s slider appeared just under seven percent of the time, with the spike curve all but forgotten (less than 4 percent of his pitches).

Cahill’s pair of fastballs weren’t especially effective, with a run value of -0.79 per 100 pitches. He pulled the string more efficiently (+0.67). But when Cahill did try to break off a slider or curveball, he often missed the mark (-1.21 for the slider, -1.54 for the curve).

Trevor’s often fell behind in the count. His first-pitch strike percentage was only 54.2%, well below the 58.2% MLB average. Finding himself in hitter’s counts so frequently might have discouraged Cahill from going to his breaking stuff. With a fastball-changeup approach, his overall contact rate was 82.1% (80.5% MLB average).

Left-handers gave Cahill some problems in the minors (his walk rate ballooned to 4.83 per nine innings vs. lefties), though nothing especially alarming. But southpaw batters battered Cahill in his introduction to the big leagues.

Baseball-Reference offers a handy stat called sOPS+, which compares a player’s performance in a given split to the league average. 100 is average. For pitchers, a mark below 100 is above-average, while a figure above 100 indicates the pitcher fared worse than the league average.

With his fastball and sinker tailing in on righties, Cahill held same-handed hitters to a 91 sOPS+ (nine percent better than the league average). But lefties? They throttled him for a 134 sOPS+.

Right-handers struggled to get their arms extended with so many pitches coming down and in. But southpaws rarely saw a pitch on the inside half of the plate:

Cahill vs. LHB, courtesy of Trip Somers’ Texas Leaguers blog:


See all that white area on the inside corner? Lefties rarely had to contend with anything in on the hands. They didn’t whiff much against Cahill:

Cahill vs. LHB (data from Baseball-Reference)
Strikeout/PA%: 11.4%
AL Avg. for RHP vs. LHB: 17.5%

Cahill didn’t exactly cause many righties to come up empty either (12 K/PA%, compared to the 17.9% AL average for RHP vs. RHB). But he did at least get same-side batters to hit the ball on the ground often. Lefties? Not as much.

Cahill vs. RHB: 52.6 GB%
Cahill vs. LHB: 45.3 GB%

(Data from Baseball Prospectus)

Trevor Cahill didn’t exactly burst onto the scene in 2009, but he really shouldn’t have been expected to do so. He had little experience above A-Ball prior to this past season, and he did manage to avoid getting embarrassed in the majors at an age where most guys are toiling in the lower levels of the minors or gearing up for their junior season in college.

In order for Cahill to live up to his promise, he’s going to have to dust off his breaking pitches and keep lefties from getting so comfortable in the batter’s box. He has a lot of work to do, but don’t get too discouraged. Cahill will only be 22 years old in 2010. There’s plenty of time for him to rediscover his whiff-inducing ways.

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A recent graduate of Duquesne University, David Golebiewski is a contributing writer for Fangraphs, The Pittsburgh Sports Report and Baseball Analytics. His work for Inside Edge Scouting Services has appeared on and, and he was a fantasy baseball columnist for Rotoworld from 2009-2010. He recently contributed an article on Mike Stanton's slugging to The Hardball Times Annual 2012. Contact David at and check out his work at Journalist For Hire.

5 Responses to “Cahill’s Lack of K’s”

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  1. MLBfan says:

    Supposedly A’s coaches did not let him throw his knuckle curve last season.Mainly FB/changeup Around midseason during his rought stretch, they just dumped the curveball all together and went to slider, cutter. he showed improvement his last 6-8 starts of the season

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  2. Lucky Strikes says:

    It be interesting to see how similar this analysis would be to one for Rick Porcello. Both extremely young, Porcello was touted as a strikeout artist as well but hasn’t developed the knack yet in the bigs. Who has the higher ceiling?

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  3. David Golebiewski says:

    Lucky Strikes,

    I took a look at Porcello’s rookie year toward the end of last season here:

    There certainly are parallels between the two, as both Cahill and Porcello were promoted aggressively and relied heavily upon their fastballs. I feel confident that Cahill will be able to miss more bats moving forward, should he mix his pitches more and stop living on the outside corner against lefties.

    As for Porcello, I’m fascinated to see what type of pitcher he becomes. Right now, he has strong groundball tendencies and above-average control. I think it’s possible that he trades some of the grounders for K’s in the future-we saw him throwing four-seam fastballs in the mid-90’s against Minnesota in October.

    I’m inclined to favor Cahill slightly, rough first season aside. Porcello exhibits better control, but Cahill has more of a track record of fooling hitters. It’s not an easy question, though.

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  4. philosofool says:

    Fan’s Projections see Porcello improving. We don’t have one for Cahil yet. (Could I make a request for Cahill to be on the list of targets in the next week?)

    I think I see Porcello as having a better shot long term. By no means is the evidence strong in favor of either, but I’ll tell you what I like about Porcello over Cahill: Porcello has a good fastball, and this gives him a pitch he can throw 70% of the time until his secondary offerings improve. Cahill, on the other hand, has a plus change up, but he’s not going to be able to throw that plus pitch more than say 20% of the time. The rest of the time, he’s throwing works in progress. Maybe this reasoning really just suggests that Cahill’s progress will be slower.

    Regardless, I think both guys are good late round targets, especially in keeper leagues.

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  5. Matty Brown says:

    Cahill has been the prospect pitcher i have paid the most attention to, since reading about him in 2007. I always knew Anderson would be a star, i just thought Cahill would come to be the next Roy Halladay. He has the tools for it and the make-up.

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