James Shields struck out 12 Blue Jays last night, completing his MLB-best 10th game of the year and joining CC Sabathia (2008) as just the second pitcher this millennium to finish what he started 10 times in a single season. Big Game is rocking a career-best 3.36 Fielding Independent ERA (FIP), and a major reason is that he's missing bats like never before by using his changeup more in two-strike counts.
At first blush, Shields' K rate this season (8.6 per nine innings pitched) looks similar to his 8.3 K/9 mark from 2010. But in this case, K/9 is misleading. Shields suffered from a .341 batting average on balls in play last year, meaning that he faced considerably more hitters per inning and had more chances to rack up Ks. In 2011, his BABIP has dipped to .267.
So, he's facing fewer hitters per inning (about 3.9 in 2011, compared to 4.4 in 2010) yet getting more strikeouts. Thus, his strikeouts per plate appearance total has climbed from 19-20 percent in past years to 24.3 percent this season, which ranks fourth among AL starters behind Brandon Morrow, Justin Verlander and Michael Pineda.
Shields owes his surging K/PA rate to more darting, mid-80s changeups in two-strike situations. From 2008-2010, he used his change about 40 percent of the time with two strikes on the hitter. He's going to the pitch 47 percent of the time with two strikes in 2011, getting more chases and misses in the process. Look at the location of Shields' changeup with two strikes in past years, compared to 2011:
He's burying more of those two-strike changeups below the knees, throwing just 32 percent of them in the strike zone (37 percent from '08 to '10). And hitters just can't resist, chasing 53 percent of those two-strike off-speed pitches tossed off the plate (51 percent from '08 to '10).
Batters are making less contact with those two-strike changeups below the knees, too:
Shields got a miss with his changeup in two-strike counts slightly less than 35 percent of the time that hitters offered at it from 2008-2010, and 42 percent of the time in 2011. The average two-strike miss rate for a changeup is 28 percent.
By relying more heavily upon his best pitch when hitters are against the ropes, Shields is enjoying his best season yet. He likely won't sniff the Cy Young Award, but he's worthy of down-ballot consideration.