Worley:Looking::Beachy:Swinging

The Phillies entered the season with the makings of an historical rotation. With Roy Halladay, Cliff Lee, Cole Hamels and Roy Oswalt, their starting pitching was covered. The Braves entered the season with ridiculous pitching depth. They had a rotation filled with good major leaguers, another solid starter recovering from surgery, and some of the most renowned pitching prospects in the game waiting to make a dent.

It’s funny, then, that the performances this season from Vance Worley and Brandon Beachy — two prospects without much minor league fanfare — have helped elevate each rotation to another level.

Worley and Beachy weren’t exactly afterthoughts, but neither was expected to be a key contributor this season. In fact, Worley started the season in the minors and spent even more time on the farm when both Oswalt and Joe Blanton returned to the rotation. Fast-forward to early September and both pitchers have tallied 2.2 WAR in under 130 innings. Both pitchers are also making a big case for their inclusion in the playoff rotation.

Despite these similarities, the major difference in their production makes a comparison interesting. Worley relies on the called strike while Beachy has become a master of the whiff. Though each is fairly inexperienced as the final month of the season pushes on, their different approaches invites a discussion on the sustainability and predictive value of called and swinging strikeouts.

First, some numbers to set the scene. Worley has thrown 110 1/3 innings this season with a 7.8 K/9, 2.9 BB/9 and 2.85 ERA. Given his decent groundball rate and low rate of homers allowed, he has a solid 3.58 SIERA. Worley has also shown tremendous improvement throughout the season, with xFIP splits decreasing successively from April-August: 4.80 to 4.36 to 4.12 to 3.46 to 2.90.

After two September starts he furthers his improvement with a 3.30 xFIP. Something clicked right around the midway point resulting in more strikeouts and fewer walks. He walked 18 in 42 innings over the first half and 18 in 68 1/3 innings since then. His K/9 rose all the way to 9.9 in August and remains around that mark this month.

The cause of his improvement is a dynamic two-seam fastball that catcher Brian Schneider decided to start calling. Schneider has essentially become Worley’s personal catcher and the two-seamer was rarely thrown prior to their battery marriage. Worley seldom threw the pitch in the minors and not until Schneider decided it worth throwing did the rookie develop the pitch. Given the nature of two-seam fastballs, a high percentage of Worley’s strikes thrown and strikeouts are of the ‘looking’ variety. Measured as a percentage of total strikes thrown — not total pitches — Worley has a swinging/looking breakdown of 9 percent/34 percent. The league average swinging strikes/total strikes rate is 15 percent, with called strikes/total strikes at 28 percent.

Contrast that with Beachy, who has emerged as a strikeout machine with a wicked swinging strike rate. He also has one of the biggest gaps between his xFIP and SIERA — xFIP has him at 3.25 against his 2.86 SIERA. Beachy’s called strike percentage is right in line with the league but he has performed well above average in terms of swings and misses. His overall strikeout rate — 10.1 per nine — is better than Worley’s for sure, but his command of four different pitches results in a much different approach on the mound. Worley relies on the movement and deception of one plus-plus pitch still in its infancy while Beachy gets called strikes but also fools hitters into empty swings.

While swinging strikes are seemingly more telling of pitcher success, they actually don’t predict future strikeout rate any better than called strike percentage. A study from Matt Swartz confirms this. Swartz looked to see whether swinging strike percentage provided more predictive value than strikeout rate alone and found the result lacking in significance. Further, he found that ‘called’ strike percentage predicted future strikeout rate in practically the same manner. ‘Swinging’ strikes had a slight advantage, one worth noting but not indicative of the idea that Worley’s success is less sustainable because batters don’t swing and miss as frequently.

Both pitchers will combine to serve as an interesting case study as their careers progress. Can Beachy sustain his gaudy strikeout rate without a real plus-plus pitch? Will the league catch up to Worley’s two-seamer? These are questions to keep in mind even after acknowledging Swartz’s study on the predictive value of strikeouts. Sometimes looking beyond overall strikeout rate paints a more accurate picture of a pitcher’s success, and this is one of those times. Both Worley and Beachy are having great seasons with good strikeout rates and different approaches.