Will Gerrit Cole be a starter or reliever come October? Pirates General Manager Neal Huntington isn't tipping his hand as the first overall pick in the 2011 draft nears an unknown organizational innings limit. Whatever his role, Cole looks primed to make make an impact in the playoffs. The rookie has boosted his strikeout rate during the season's second half (from 5.4 per nine innings pitched to 7.9 K/9) and trimmed his ERA from 3.89 to 3.18.
Cole fell in love with his fastball early on during his big league career, but he's pitching more like the ace he's expected to become now that he's mixing in his breaking stuff.
During the first half, Cole threw his fastball about 77% of the time -- more often than any starting pitcher not named Bartolo Colon. In the second half, he's throwing his heater about 67%. The difference is even more pronounced in two-strike counts: 66% fastballs in the first half, and slightly under 54% in the second half.
In place of those fastballs, Cole is snapping off signifcantly more short-breaking, upper 80s sliders (six percent overall in the first half, 21% in the second half). He's throwing his low-80s curveball at about the same frequency (12% in the first half, 10% in the second). Cole is using his slider and curve as chase pitches far more often in the second half, particularly with two strikes:
Location of Cole's slider and curveball in two-strike counts during the first half
Location of Cole's slider and curveball in two-strike counts during the second half
Cole threw 44% of his two-strike sliders and curves in the strike zone during the first half, well above the 39% big league average for starters in such situations. In the second half, he's throwing just 33% of his two-strike breaking balls over the plate. Cole got eight strikeouts with his slider and curve in the first half. During the second half? Thirty.
Throwing more breaking pitches out of the zone has helped Cole put hitters away in two-strike counts. Opponents hit .246 and slugged .290 against Cole when down to their last strike during the first half (starters overall allow a .172 average and .257 slugging percentage in two-strike counts). Now that he's using his slider and curve, he's limiting batters to a .151 average and a .264 slugging percentage with two strikes. Starter or reliever? Only Huntington and manager Clint Hurdle know. Either way, Cole looks postseason-ready.