The unhittable pitch rocking this MLB postseason -- and the aces who will be throwing it in World Series Game 6

"TORONTO -- In Game 6 of the World Series on Friday, two of the foremost practitioners of the pitch that has defined October will duel at Rogers Centre. Los Angeles Dodgers right-hander Yoshinobu Yamamoto is trying to save his team's season, and Toronto Blue Jays right-hander Kevin Gausman is trying to win his franchise's first championship in more than 30 years, and both will rely heavily on the split-fingered fastball, an offering that for almost 20 years teetered on the brink of extinction in Major League Baseball."

"The rise of the splitter over the past half a decade -- fueled by the emergence of elite pitching from Japan, where the the offering is a standard part of nearly every pitcher's arsenal, and the softening on its use by MLB teams that at one point had forbid the pitch, fearful that it directly led to elbow injuries -- has transformed baseball even more than the cutter and sweeper once did. Because it's a superior pitch to all of them."

"In recent years, Kershaw began throwing a split-change, finally finding a comfortable variation of a changeup after spending his 18-year future Hall of Fame career in search of one. He is far from alone. This postseason, 32 pitchers, representing nearly a quarter of playoff hurlers, have thrown splitters. Since the advent of pitch tracking in 2008, the highest percentage of splitters thrown among overall pitches in October was 3.2% last year. Most seasons, it ranged between 0.2% and 2%."

Yoshinobu Yamamoto and Kevin Gausman will both rely heavily on the split-fingered fastball in a pivotal World Series start. The splitter has resurged after nearing extinction, driven by elite Japanese pitchers who use it routinely and by MLB teams relaxing earlier bans motivated by injury concerns. Usage has climbed sharply this October, with 32 postseason pitchers throwing splitters and split-percentage rates well above historical October norms. Individual reliance is pronounced: Gausman has used the pitch over 40% of the time in the playoffs, Yamamoto near 25%, and rookies and stars have deployed it effectively in recent postseason games.

Read at ESPN.com