Travis Wood's Cutter: Changing Approach, Results

In the midst of his second season as a member of the Chicago Cubs' starting rotation, 26-year-old Travis Wood has quietly staked his claim as one of baseball's best left-handed starters as exhibited by his selection to the NL All-Star squad.

Posting a 4.27 ERA and 1.20 WHIP over 26 starts with Chicago in 2012, Wood has lowered his earned run total by nearly two, boasting a 2.69 ERA and 0.98 WHIP over 17 starts so far this season, which rank fourth and fifth-best, respectively, among qualifying southpaw starters.

Wood's Improved Cutter

What's stood out in particular this season for Wood, compared to last, has been the effectiveness of his cutter against right-handed batters.

Wood's  Cutter Against Righties	2012	2013
BAbip	.295	.206
SLG%	.491	.310
HR/FB%	10.9%	6.8%

• Right-handed batters have struggled to tally up extra-base hits at the same frequency in which they did last season, evidenced by a slugging percentage reduction of .181.
• They have struggled to find holes in defenses, shown by Wood's .206 BAbip, which ranks as the lowest mark among qualified left-handed starters this season.
• Home runs have been hard to come by compared to last season, and Wood's 6.8% home-run-to-fly-ball rate ranks as the sixth-best among qualified left-handed starters in 2013.

Wood's improvements can be traced to his command of the pitch.

Pitch frequency of Wood's cutter and BABIP of right-handed hitters in 2012

• Last season, Wood struggled to command the pitch to any one region of the strike zone and mainly left the pitch up belt-high. Due to that, plus the angle of the pitch coming across the plate, right-handed batters lit up any cutter left over the outside portion of the plate, which resulted in a .295 BAbip mark for the season.

And this season:

• This season, Wood has strayed away from jamming right-handed batters on the inside portion of the plate with the pitch, as he did in 2012. Instead, he has concentrated his cutter more toward the middle and outer portion of the plate.

Good Movement

Of course, command is reliant on other variables, such as movement of the pitch and Wood's cutter is no exception.

Wood's Cutter	2012	2013
Horizontal Velo. Across Plate	-5.5 ft/sec.	-4.8 ft/sec.
Vertical Break	7.0 in.	8.6 in.

Wood's cutter has had less horizontal velocity across the plate this season compared to last, but has on average had more vertical break to it than last season. This reduction in horizontal velocity is the main reason why the pitch has been less focused on the inner portion of the plate against right-handed batters, and the increase in vertical break could be why right-handed batters are struggling to put quality contact on the ball this season compared to last.

Unless right-handed batters are willing to adjust to the changes in movement and improving command of the pitch, Wood's cutter could make him what manager Dale Sveum called him earlier in the season -- baseball's best pitcher.