(Photo by Ronald Martinez/Getty Images)

On July 30, 2011, the Baltimore Orioles pulled off, what would later turn out to be, a lopsided trade. They sent right-handed reliever Koji Uehera, then 36, to the Texas Rangers in exchange for hard-throwing erratic right-hander Tommy Hunter and undeveloped power hitter Chris Davis. By 2013, the Orioles had a setup-man-potential-closer-in-waiting in Hunter and an all-star and home run champion in Davis. Uehara tossed only 54 innings and posted a 2.50 ERA for the Rangers over a season and half, limited by injury. That, however, wasn’t the end of Uehara.

The Red Sox signed the 38-year-old and former Japanese all-star to a one-year, $4.25-million deal, hoping the veteran could bolster the bullpen as a setup man. But after injuries to Andrew Bailey and Joel Hanrahan, Uehara assumed the role of closer by late June. What followed over the final three months of the season capped one of the most dominant relief seasons in history. It is an excellence that has carried over to the playoffs, where he has notched 10 important outs for the Red Sox that has helped propel them to a two games to one lead over the Detroit Tigers in the American League Championship Series.

“It’s like he’s playing on a different planet right now,” starter Jon Lester said of Uehara, who struggled in his previous playoff outings with the Rangers in 2011 and 2012.

After a career in Japan as both a starter and closer, Uehara left the Yomiuri Giants and signed a two-year deal with the Orioles in 2009. He failed as a starter in 2009, posting a 4.05 ERA over 12 starts and dealing with injuries, before excelling as a reliever in 2010, a 2.86 ERA over 44 innings. Each passing season, Uehara’s ERA lowered, coinciding with the increased usage of his superb split-finger fastball.

The pitch, which was on display over the final four outs of the Boston’s 1-0 win in Game 3, dives hard and away from left-handers. The way the ball moves is unfair to batters. Uehara threw the pitch over 48 percent of the time in 2013, averaging only 81 miles per hours but producing a .096 opponents batting average. (For a fascinating look at Uehara’s pitching, including detailed animated GIFs, read this Baseball Prospectus story.)

Uehara went on to save 21 games in 24 chances for the Red Sox this season. He finished with ungodly numbers: a 1.09 ERA over 74 1/3 innings, only nine earned runs, nine walks, 101 strikeouts, a 0.565 WHIP, 12.2 K/9 and 11.22 K/BB (!). He is known for his exuberant celebrations and loud, hard high fives that almost snaps teammates’ bones in half. At one point this summer, retired 37 straight (!) batters before coughing up a triple to Baltimore’ Danny Valencia, just four batters shy of the all-time record of 41 straight retired by Bobby Jenks in 2007. That’s a span of 30 2/3 innings over 27 games without allowing a run. That’s mind-boggling.

Uehara has already saved three games this postseason. He has lost one game, on an improbable home run swing by Tampa Bay’s Jose Lobaton in Game 3 of the ALDS. But of those three saves, two have been of the four-out variety. He has proven so valuable, durable and unfathomably good for the Red Sox this season that should they carry another lead into the eighth inning in the playoffs, expect Uehara, his wicked splitter and his quirky style to be on full display.


Dodgers vs. Cardinals
4 p.m. on TBS; Cardinals lead the series, 3-1.
Probables: RHP Joe Kelly (10-5, 2.69 ERA in the regular season) vs. RHP Zack Greinke (15-4, 2.63 ERA)

Red Sox vs. Tigers
8 p.m. on FOX; Red Sox lead the series, 2-1.
Probables: RHP Jake Peavy (12-5, 4.17 ERA in the regular season) vs. RHP Doug Fister (14-9, 3.67 ERA)