Cahill and K's

The Arizona Diamondbacks fortified their rotation over the weekend, acquiring Trevor Cahill (and reliever Craig Breslow) from the Oakland A's for a trio of prospects: RHPs Jarrod Parker and Ryan Cook and OF Collin Cowgill.

Parker is nearly big league-ready and has big upside, having returned from Tommy John surgery to post a 112/55 K/BB ratio in 130.2 innings at Double-A Mobile and then impressing enough in a late-season cameo to earn a postseason roster spot.  Diamondbacks GM Kevin Towers says the club is in "go-for-it mode," taking advantage of a window to retain top status in the NL West. However, Towers is no doubt aware that Cahill -- signed through 2015 for a little under $29 million, with team options for 2016-2017 worth a combined $26.5 million -- is a long-term buy with remaining upside.

Cahill (24 in March) has been a slightly above league-average starter to this point in his career, sporting a modest strikeout rate (5.5 K/9), average control (3.3 BB/9) and strong ground ball tendencies (54%). But the right-hander, who whiffed nearly 10 batters per nine innings as a prospect, is starting to miss more bats in the big leagues. He struck out just 11.6% of hitters faced as a rookie in 2009, but he increased that total to 15.1% in 2010 and fanned 16.3% of batters faced in 2011 (the average for starters is 17-18%).

He's getting more Ks by incorporating his breaking pitches more often. Cahill threw his his-70s curveball and his short-breaking, low-80s slider just 10 percent of the time as a rookie. As a sophomore, he threw his breaking stuff 15 percent, and he tossed a curve or slider 19 percent in 2011. Cahill is progressively doing a better job of keeping those breaking balls down, and hitters are swinging over his low curves and sliders.

In 2009, Cahill caught the middle part of the plate often with his curve and slider:

Location of Cahill's curveball and slider, 2009

Fifty percent of his breaking balls were located low in the zone, 29 percent were thrown to the middle portion, and 21 percent were thrown high. Hitters just about never missed those middle and high breakers:

Opponent contact rate by pitch location vs. Cahill's curveball and slider, 2009

Hitters swung and missed at Cahill's curve just 22 percent of the time overall, well below the 28 percent average for starting pitchers. In 2010, Cahill did a bit better in keeping the ball down:

Cahill's curveball and slider location, 2010

He threw 52 percent of his breaking pitches low in the zone, 27 percent to the middle, and 21 percent high in the zone. Those curves and sliders spotted low in the zone induced lots of whiffs:

Opponent contact rate by pitch location vs. Cahill's curveball and slider, 2010

Opponents missed 35 percent of the time they swung at a Cahill breaker. This past season, Cahill very rarely hung a curve or slider:

Cahill's curveball and slider location, 2011

Cahill threw 58 percent of his breaking balls low, 22 percent to the middle of the zone, and 20 percent to the upper third of the zone. Those breaking pitches thrown to the arm side gave hitters fits, and Cahill slightly increased his miss rate with his curve and slider to 36 percent:

Opponent contact rate by pitch location vs. Cahill's curveball and slider, 2011

At worst, the Diamondbacks picked up a young, cost-controlled starter who has gradually increased his workload to 200+ innings and will complement Dan Hudson and Ian Kennedy nicely. But, with Cahill becoming increasingly comfortable using breaking pitches in addition to his quality sinker and changeup, he could yet take a leap forward and become a number two or fringe number one starter. Some think Parker has that upside, too. Still, considering that the D-Backs have an absurd amount of pitching prospects in the pipeline -- Trevor Bauer, Archie Bradley and Tyler Skaggs to name a few -- picking up Cahill is a solid move that improves the team in 2012 and beyond.

Arguing the Strike Zone in the A's-Red Sox game

Last night, both Jason Varitek (BOS) and Jonathan Papelbon (BOS) were ejected in the top of the ninth inning for arguing the strike zone with home plate umpire Tony Randazzo.  Varitek was ejected first after a Cliff Pennington (OAK) double that cut the Red Sox lead over the A's to two runs.

First, let's look at all the called balls Papelbon had from the game:

10 Pitches (Click image to enlarge)

And here's Papelbon's called ball rate heat map from that ninth inning which incorporates all the pitches he threw:

28 pitches (Click image to enlarge)

Other than that one spot middle-down, Randazzo really didn't miss any called strikes.  And as for that missed strike call?  Well, it was the third pitch of Landon Powell's plate appearance.  Papelbon had him 0-2 and that should have ended the atbat.  But it did little to effect the inning because he eventually struck Powell out swinging on the 7th pitch.

Kevin Youkilis also gave Randazzo a hard time after the ump rang the Red Sox third baseman up on a Brad Ziegler (Oak) curveball in the 8th inning.

(Click image to enlarge)

Ziegler started him out with two sinkers, and finished with two curveballs which both caught the outside of the plate, the last well within the pitchFX defined strike zone.

Ironically, one of the biggest missed strikes from last night came while Youkilis batted in the 4th inning.  Oakland starter Trevor Cahill threw him a 3-2 curveball that seemed to land right in the middle of the plate, yet was called ball four.

(Click image to enlarge)

Cahill's sixth, and last pitch of the AB looks to have caught more than enough of the plate, but Randazzo didn't see it that way.  The first pitch, a changeup, was also called a ball by Randazzo, but appears to have caught the corner.  Cahill would get David Ortiz (BOS) to hit into an inning ending double play two pitches after walking Youkilis, however.  So much like the missed called strike to Powell in the ninth, no harm done.

Trevor Cahill's Sinker: Luck or Skill?

Trevor Cahill had a fantastic year for the Oakland A's in 2010.  He was very successful in keeping the ball down, as he went from a 96 ERA+ in 2009 to a 136 ERA+ last season.  Some have noted that his very low overall BABIP (.237) is partially responsible for his success, rather than any particular ability to induce weak ground balls.  However, a closer look possibly indicates that luck may not have played as big a role in Cahill's success.

Cahill was one of the most successful ground ball pitchers in the majors; 56% of batted balls off his pitches ended up on the ground in 2010, 5th highest in the majors.  As you can see from the heat map above, he became very efficient at keeping his pitches down last season.  His GB/FB ratio went from .92 to 1.32 in one year.  The main reason: his excellent sinker.

Cahill's 2010 sinker was flat out nasty, averaging 14.8 feet per second of downward movement, putting him in the top 10 percent of sinkerballers.  This makes it tougher to chalk up his basement low .153 batting average on ground balls (best in the majors) to mostly luck.  He's obviously benefitting greatly from the movement he's getting on his sinker. If batters are finding it harder to makes solid contact as a result of that increased movement, it's possible they are hitting weaker ground balls; in turn, this would make it easier for his defense to field and turn these ground balls into outs. 

This is not to say that we won't see some regression this year.  It's certainly possible that a good chunk of these ground balls were simply finding infielders, particularly when well hit. But if he can keep his pitches down and moving as they did last year, don't be surprised if his overall BABIP remains in the cellar.