Relief pitchers usually find themselves in the bullpen because they don't have a wide variety of pitches they can throw to keep batters on their heels over the course of six or seven innings.

So with a usually limited repertoire, a reliever better have a dynamic pitch or two that can carry him throw an at-bat or an inning. Think Mariano Rivera and his legendary cut fastball.

Rangers reliever Sam Dyson possesses that pitch in his sinker, which was recently named the ninth-best pitch in the Major Leagues by stat-guru Eno Sarris in a special piece for ESPN.

What makes Dyson's sinker so unique is that it was the lowest of the top 10 in swinging-strike percentage at 10 percent but is the second-highest on the list with an 80-percent ground ball rate per pitch. Sarris values swinging-strike percentage more than ground ball rate because according to his calculations "swinging strikes are, on average, twice as important as ground balls."

But the low swinging-strike ratio does not hurt Dyson's sinker's value, a pitch the Ranger threw 565 times last season at an average velocity of 95.6 miles per hour. The sinker's final score in Sarris' formula (2*(swinging-strikes z-score) + 1*(ground ball rate z-score) = quality of each pitch judged against other results in that pitch type) came out to a 6.7, behind Darren O'Day's fastball and ahead of Hunter Strickland's fastball for ninth place in all of the MLB.