Along the way, the 25-year-old Japanese star has become a strikeout artist. Across 22 innings in pinstripes, Tanaka has struck out 28 batters.
That figure is good for an 11.45 K/9 rate and enough to raise eyebrows around baseball. When the Yankees allotted $175 million—including a $20 million posting fee—to secure the services of baseball's most interesting free agent, it was clear that a young, durable starter with the potential for excellence was headed to New York.
During a seven-year career in Japan, Tanaka won 99 games, pitched to a 2.30 ERA, threw over 1,300 innings and completed a perfect season (24-0) in 2013. Finding reasons to believe in Tanaka's ability to transition to Major League Baseball wasn't a difficult task; however, a dominant strikeout ratio likely wasn't part of the Yankees' belief in their big-ticket item.
In Japan, Tanaka averaged 8.5 K/9 during his career and actually saw his strikeout rate dip to 7.8 K/9 last year. Despite a 1.27 ERA and undefeated personal record, Tanaka wasn't striking out the majority of hitters in Japan.
If strikeout dominance wasn't on the scouting reports for opposing teams when the season began, it likely will be very soon. After back-to-back-to-back outings of at least eight strikeouts, the Toronto Blue Jays, Baltimore Orioles and Chicago Cubs can attest to Tanaka's swing-and-miss stuff.
Masahiro Tanaka (8 K's today) joins Stephen Strasburg as the only pitchers in the last 100 years with 8+K in each of first 3 MLB starts— ESPN Stats & Info (@ESPNStatsInfo) April 16, 2014
Over his last two starts—including Wednesday afternoon's 10 K/1 BB effort against the Cubs—Tanaka has tallied consecutive double-digit-strikeout performances. Last year, only four starters reached that feat more than five times over the course of the full season, per Baseball-Reference (subscription required).
Assuming health, Tanaka has 30-plus starts left to match a feat reached only by Yu Darvish, Max Scherzer, Chris Sale and Matt Harvey last season. Due to an incredible strikeout-to-walk ratio (28-2), Tanaka currently sports an FIP (fielding independent pitching) of 1.01, tops in baseball.
So, what happened? How did an excellent but not overpowering Japanese pitcher arrive in America with the ability to miss bats so frequently?
To be fair, small sample size is still in play. Tanaka's first 22 big league innings have been very, very impressive, but that's far from 222 innings of excellence. If this dominance continues for another few starts, however, it might signal that the Yankees have a special arm on their staff.
In the history of baseball, only 12 individual seasons have been recorded in which a starter averaged at least 11.45 K/9 across 200-plus innings. Right now, that's the number Tanaka is averaging for the young season. You may have heard of the five pitchers on this list.
Tanaka's early-season success is rooted in many factors. From pitching ahead in the count to confidence to command, simplifying the numbers would be foolish. With that said, one pitch is paving the way: the splitter.
According to BrooksBaseball.net, Tanaka's great splitter has generated a 35.56 whiff percentage. To put that into perspective, Clayton Kershaw's curveball—considered one of the best singular offerings in baseball today—had a whiff percentage of 14.46 last season. Last season—on the path to a K/9 mark of 11.9—Yu Darvish didn't have one individual pitch that generated a whiff percentage of higher than 23.32.
Renteria on Tanaka: “That splitty isn’t one you want to sit on. As guys were coming in they were saying ‘it looks like a fastball.’"— Jesse Rogers (@ESPNChiCubs) April 16, 2014
Hyperbole aside, Tanaka's splitter is one of the best pitches in baseball right now. To the naked eye, it's the best splitter since Roger Clemens was in his prime. According to ESPN Stats and Info, a big part of the reason for the success of this splitter is deception.
Notice the almost identical trajectory of the two distinct pitches. With similar velocity on each offering, hitters can't immediately dissect the difference between each pitch. Considering the little time major league players have to make a decision on how to approach each pitch, Tanaka's deception is enough to fool good hitters into swinging at splitters in the dirt.
Prior to Wednesday's outing against the Cubs, the velocity difference on Tanaka's fastball and split was less than 5 mph. When the ball leaves his hand, it's nearly impossible to differentiate the pitches. By the time the nominal velocity difference is evident, the ball is falling off its trajectory and to the ground, leaving hitters almost no chance to lay off.
Part of the rise in Tanaka's strikeout rate is due to the overall rise in strikeouts in Major League Baseball. Early in 2014, American League starters are averaging 7.55 K/9, up from 7.18 in 2013 and 6.96 in 2012, per ESPN. Those numbers are instructive, but as Mike Axisa of River Ave. Blues pointed out in February, the strikeout average was 6.7 K/9 in Japan last season.
How many strikeouts will Masahiro Tanaka have this season?
An uptick in Tanaka's overall strikeout rate was to be expected due to philosophical differences between leagues, but this is unprecedented. It's hard to imagine a rookie starter dominating the American League East with huge strikeout rates all summer long, but Tanaka's first three starts were uniquely impressive.
With a devastating out pitch, strikeout rates soaring around baseball and an unknown element to his arsenal, the idea of an AL Rookie of the Year campaign highlighted by 200-plus strikeouts isn't far-fetched for the expensive Japanese import.
Statistics are from Baseball-Reference.com and FanGraphs unless otherwise noted. Brooks Baseball data valid through Tanaka's first two starts. All contract figures courtesy of Cot's Baseball Contracts. Roster breakdowns via MLB Depth Charts.