Orioles' closer Zach Britton is having an even better season in 2015 than last, the first in which he headlined Baltimore's bullpen. In 36.2 innings pitched, Britton has a sterling 1.72 ERA, 1.84 FIP, and has accumulated 1.1 fWAR.
His elite 75.0 percent ground ball rate leads all qualifying relievers, and on top of that he has added an above-average 28.9 percent strikeout rate over what has been a more pedestrian number in the past. The resulting 1.30 SIERA would be the fifth-best single-season rate for a reliever in the PitchF/X era.
Each of his ground ball, strikeout, 5.8 percent walk, 13.7 percent swinging-strike and 19.4 percent hard-hit rates are the best figures of his career. Additionally, in what is still a small sample as a closer, Britton has dramatically increased his outside-swing percentage while decreasing his zone-swing percentage, a rare feat.
Zach Britton is doing everything basically as well as one could reasonably expect for a closer in 2015. Per Brooks Baseball, his elite sinker has averaged 96.9 mph this season, while his curve sits at a high 84.1 mph.
Both pitches feature a large amount of horizontal movement, with the fastball breaking 8.8 inches on average and the secondary moving -4.5. In terms of drop, Britton's sinker has consistently dropped further every season of his career, to a new low in 2015.
He relies very heavily on that sinker (89.9 percent usage), and opposing batters have a very poor 76 wRC+ against the pitch (particularly bad against a fastball). A pitch thrown that hard with that much movement is almost impossible to hit solidly, as evidenced by his career-high 34.4 percent soft-hit rate.
In 2015, Britton is mixing in a little bit more of his curve ball to great effect, as batters have hit .071 with a .000 ISO against the pitch. In addition to the higher velocity and tighter break on that pitch, Britton's stellar season is being propelled by career high velocity and drop on his fastball along with a career-high 67.8 percent strike rate. His strikeout rate has jumped to the elite reliever tier in addition to a very low walk rate and ridiculous ground ball rate. An astounding 78 percent of all Britton's plate appearances end in either a strikeout or ground ball.
Zach Britton might not be the first name that comes to mind when thinking of the potential 'best closers in baseball,' but maybe he should be. He is doing everything in his power to earn that title.
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Spencer Bingol is a contributor at Beyond the Box Score. You can follow him on Twitter at @SpencerBingol.