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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.