Will Tanaka's Game Translate to Major League Baseball?

Japanese players are taking over Major League Baseball's American League.

Just look at voting for the 2013 AL Cy Young Award: Yu Darvish finished second, Hisashi Iwakuma finished third, and Koji Uehara finished seventh.

The Yankees’ Hiroki Kuroda finished 11th in the AL in ERA, and Junichi Tazawa of the Red Sox tied for 10th in the AL in games played.

As of Tuesday, five of the only six Japanese pitchers in the big leagues were in the American League, and three of them earned Cy Young votes. On Wednesday January 22, 2014, the New York Yankees, not wanting to miss out on the phenomenon, inked Masahiro Tanaka to the fifth-largest contract ever signed by a pitcher in MLB history - a seven-year, $155-million deal.

Who is Masahiro Tanaka?

Masahiro Tanaka is a 25-year-old right-handed starting pitcher who played his last seven seasons for the Tohoku Rakuten Golden Eagles. He has been described by scouts as intense, ultra-competitive, and someone who pitches with passion. His fastball usually sits in the 91 to 94 mph range, and has reached 97 on occasion. It’s thrown with terrific accuracy, but some scouts worry that due to a pronounced stride, it comes in on too flat of a plane with too little movement that it might be more hittable than his stats suggest.

His best pitch is his splitter, which is often described as more of a forkball. He typically keeps it in the mid-80s and commands it well to both sides of the plate. On the 20-80 scale scouts use, it’s considered a 70 with Uehara and Kuroda being the best comparisons.

His primary weapons are the fastball and splitter - his splitter being his go-to pitch - yet he also wields a plus slider. Batters had a hard time making contact with it, but it also seemed to get away from him at times. On top of these three pitches, he also has a curveball and a cutter somewhere in the back of his arsenal. While most scouts don’t think he’s going to be better than fellow Japanese star Yu Darvish, many believe he has the potential to one day become the ace the Yankees are hoping for.

Not uncommon for Japanese pitchers, Tanaka came into the Nippon Professional Baseball league (NPB) in 2007 at 18 years old. Though this was the only year where his ERA was above the league average, he still managed to win the Rookie of the Year award.

The following year, Tanaka brought his ERA down to 3.49. The next two years, his ERA stood at 2.33 and 2.50 respectively. Then, in 2011, the NPB switched balls, and Tanaka put up numbers that the NPB hadn’t seen since 1970. In 2011, he led the league in wins, ERA, complete games, shutouts, and strikeouts. This was also Yu Darvish’s last year in the NPB; his ERA (1.44) was slightly higher than Tanaka’s (1.27). He continued to thrive over his next two years in the league. His ERA went up to a still very impressive 1.87 in 2012 and then back down to the incredible 1.27 he had two years prior.

Tanaka had one of the most impressive performances in NPB history last year. He led the league in wins, ERA and WHIP, won the Pacific League MVP, broke the all-time NPB record for consecutive wins by a pitcher, and helped lead his team to a championship victory over the Yomiuri Giants. In 28 GS and 212 IP (an average of throwing almost 8 innings per game started), he had a 24-0 record with 183 Ks, 1.27 ERA, and a 0.94 WHIP. If these were major league stats, he’d be tied for the most wins since 1990 and the best ERA since Bob Gibson in 1968. These, however, are not MLB numbers, which begs the question: What will his MLB stats be?

Tanaka in the MLB

For years, I’ve heard that, besides the level of talent (of course), there are several other differences between the MLB and the NPB; the strike zone in Japan is slightly bigger, their ball size is slightly smaller, and pitchers start every seven days instead of the five our pitchers are typically accustomed to.

Up until several years ago, an important part of scouting Japanese pitchers was in measuring the size of that player’s hands. Could they accommodate for the bigger ball? How much would it affect their accuracy, the speed of their fastball, or the movement on their curve?

Now, this is mostly a thing of the past. In 2011, Japan switched balls from a slightly smaller size to match the bigger American balls. Upon doing this, however, they saw home runs drop by almost 35% over the next two years. In 2013, to compensate for the drop in home runs, the league secretly tweaked the ball in hopes of increasing the home run rate and drawing more fans back to the stadium. By June, home runs were up 60% by the same time the previous year.

Confirmed by a former MLB and NPB pitcher C.J. Nitkowski, "inside strikes tend to get called more often in the NPB," so the strike zone may actually be a bit bigger. Japanese pitchers are given more rest in between starts, but also typically last for more innings per game than their American counterparts. Furthermore, American mounds are said to be of a harder consistency than those in Japan.

All of this being said, there are plenty of differences between the two leagues. However, that doesn't mean we can't try to get a decent idea of how Tanaka will perform in America.

Digging Into the Numbers

To project Tanaka's potential in 2014, I first collected the names of the seven most famous Japanese starting pitchers in MLB history, calculated the stats from their final three years in the NPB, and compared these numbers to Tanaka’s 2009 and 2010 stats. The results are below.

Pitcher	Seasons	ERA	WHIP	K/9	HR/9
Masahiro Tanaka	2009-10	2.41	1.13	7.58	0.58
Yu Darvish	2009-11	1.64	0.91	9.72	0.27
Hisashi Iwakuma	2009-11	2.87	1.16	6.70	0.59
Hiroki Kuroda	2005-07	2.87	1.09	6.70	0.76
Daisuke Matsuzaka	2004-06	2.40	1.03	9.10	0.54
Kei Igawa	2004-06	3.50	1.26	8.78	1.07
Hideki Irabu	1994-96	2.70	1.16	10.23	0.50
Hideo Nomo	1992-94	3.30	1.39	9.89	0.69

For the sake of a more accurate comparison, I threw out Tanaka's numbers during the dead-ball era of Japan (2011-2013) and only included his stats from 2009-2010. When I had included his dead-ball era stats, he had a 1.44 ERA, 0.94 WHIP, 8.37 K/9, and a 0.27 HR/9. In other words, they weren't very accurate or worthwhile to look at given the way the game changed.

I kept Darvish and Iwakuma’s 2011 stats in the calculation to be a little tougher on the new Yankees’ star. Still, in spite of this, he has the best numbers in the chart behind only Darvish and Dice-K.

Next, I wanted to take a look at how these pitchers all fared during their first season in the bigs.

Pitcher	Season	ERA	WHIP	K/9	HR/9
Yu Darvish	2012	3.90	1.28	10.40	0.70
Hisashi Iwakuma	2012	3.16	1.28	7.30	1.20
Hiroki Kuroda	2008	3.73	1.22	5.70	0.60
Daisuke Matsuzaka	2007	4.40	1.32	8.80	1.10
Kei Igawa	2007-08*	6.66	1.76	6.70	1.90
Hideki Irabu	1997	7.09	1.67	9.50	2.50
Hideo Nomo	1995	2.54	1.06	11.10	0.70

*Kei Igawa's first two years were added together for his first year stat line because he only played two games in his second and final season.

Of these seven pitchers, most saw their ERA jump by 80% or more when comparing their first-year numbers to their NPB ones. Hideo Nomo managed to beat this trend and put together a marvelous first-year transition to the MLB - unlike the other pitchers, his ERA actually decreased by about 23%! His WHIP dropped by 24% and his K/9 jumped from 9.89 to 11.1. Unsurprisingly, Nomo had the best season out of this group, followed by the three most recent MLB imports in Iwakuma, Darvish, and Kuroda. Nomo's numbers being atypical, it's not unreasonable to expect a significant decrease in production. On average, it seems as though a Japanese pitcher in their first year in the majors should expect to see their ERA increase by about 70%, WHIP by about 22%, HR/9 by 118%, while their K/9 should stay about the same.

In the next table, you'll see how these pitchers performed over their entire MLB careers.

Pitcher	Seasons	ERA	WHIP	K/9	HR/9
Yu Darvish	2012-13	3.34	1.17	11.20	0.90
Hisashi Iwakuma	2012-13	2.84	1.10	7.50	1.10
Hiroki Kuroda	2008-13	3.40	1.18	6.80	0.90
Daisuke Matsuzaka	2007-13	4.52	1.41	8.20	1.00
Kei Igawa	Â	n/a	n/a	n/a	n/a
Hideki Irabu	1997-02	5.15	1.41	7.10	1.60
Hideo Nomo	1995-08	4.24	1.35	8.70	1.10

While Nomo got off to a terrific start, his production waned towards the end of his career. Iwakuma, Darvish, and Kuroda have the clear advantage in this category. Though it should be noted that this is perhaps because they are still at the heights of their career, so their numbers to date are still quite remarkable.

Iwakuma might have the most impressive statistics in comparison to his NPB numbers. He's the only pitcher here who has a lower career ERA in the MLB than in the NPB. His ERA dropped by 1%, his WHIP dropped by 5%, and his K/9 increased by a healthy 11.9%. The second closest pitcher was Kuroda, who only saw an ERA increase of 18.5%.

On average for their career, a Japanese pitcher's ERA goes up 55% and WHIP goes up by 14.5%, while their K/9 and HR/9 stay consistent with their rookie numbers. These numbers are a good deal better than their rookie figures, so it appears most Japanese pitchers do require an adjustment period of at least one year.

Tanaka in 2014

Based on all this, we may be able to get a general idea - albeit one that stems from a small sample - of how Tanaka will perform in 2014.

As I mentioned before, using his recent numbers won't give us a great idea of how he'll do given the dead-ball era. Had we used his recent numbers, I'd project him to have a 2.45 ERA, 1.14 WHIP, 8.47 K/9 and a 0.59 HR/9. Clearly, a line like that would have made Tanaka the best pitcher in the American League last year.

The chance of that happening isn't good. Like many NPB pitchers in 2011 and 2012, his ERA was significantly bolstered by the change in ball size and the NPB hitters’ inability to adjust to it. So, instead I used the numbers he put up two years prior as the reference point.

Pitcher	ERA	WHIP	K/9	HR/9
Masahiro Tanaka	4.10	1.37	7.35	1.26
% change	70.2%	21.6%	-3.0%	117.8%

When using his 2009-2010 numbers, Tanaka projected out to an expected line of a 4.10 ERA, 1.37 WHIP, 7.35 K/9, and a 1.26 HR/9 next year with a career line of 3.73 ERA, 1.29 WHIP, 7.28 K/9, and a 1.26 HR/9.

I think these numbers are a much better indicator to what we should actually expect, but I don’t think they still represent the whole picture. While the two (maybe three) years of pitching in the dead-ball era helped his stats a great deal, most scouts agree he did become a much better pitcher during that time period. Also, he won’t have as hard of a time adjusting to the size of the ball as many of his fellow expatriates may have had, seeing as how he’s used it the past three years and in the World Baseball Classic. I think his numbers will be close to Darvish’s first-year stats, but with a slightly better ERA and a lower K/9. Here's my actual prediction:

Bear: 9 W, 4.10 ERA, 1.35 WHIP, 7.35 K/9
Base: 11.5 W, 3.65 ERA, 1.25 WHIP, 8.25 K/9
Bull: 14 W, 3.35 ERA, 1.18 WHIP, 8.7 K/9

Tanaka's a terrific pitcher, and he has a great career ahead of him, but I’m not expecting Cy Young numbers from the start. In a best-case scenario, I have his ERA at 3.35, while it would be at 4.10 in a worst-case one. I think the base here is the most accurate representation for what he’ll do next year.

That being said, I'm not sure the Bronx was a great landing spot for him. Owning a pitcher on the Yankees used to be good news for anyone in a league where ‘wins’ counted as a category. After all, since 2004, they’ve only not finished in the top two in scoring twice. However, one of those years was last season where they finished 16th. And while they did make some big free agent acquisitions this year, they still lost Curtis Granderson and Robinson Cano.

In addition to weaker run-support than typical, the stadium itself isn't very good for pitchers. With its short porch in right field, it consistently ranks as one of the best places for home runs. It will be interesting to see what this impact will have on Tanaka's stats; for the Japanese pitchers mentioned above, their HR/9 increases by an average of 117.8% their first year in the MLB. The bullpen looks in rough shape, especially with Mariano leaving, but most importantly, their infield is a mess on defense. If he had signed to a team with a better defense, I may have knocked .1-.2 off of his ERA and WHIP.

So while I think he's a solid pitcher and should have a good career, we should temper expectations for his first year, especially considering his situation.