The Japan to MLB Transition... For Pitchers!

With all this talk about Yu Darvish being posted, it seemed appropriate to take a look at previous Japanese league players and how their statistics translated to Major League ball. This may provide some insight into what we may expect from Darvish if the Sox were to end up winning his posting. I'll look at players that were posted or came over in free agency, but will eliminate those who I consider to have been prospects or in development still (like our own Tazawa). Also limiting this to starting pitchers only, I think the transition for relievers is a little different because the relief game is so different. I'll take a look (if I can find the data) at their last three years in Japan and compare it to the first three of their MLB careers, largely because those three years will have the most relevance to their MLB play and it would be enough to notice any trends. After three years, I think we can largely identify what we have in a player. I'll focus mostly on the rate stats rather than the counting ones. I won't be using any advanced stats, largely because I'm lazy and don't want to do them out by hand since I can't seem to find them already calculated elsewhere, so ERA and WHIP it is...

Daisuke Matsuzaka:

Last 3 years in the Japanese Pacific League:

2004: 2.90 ERA, 146 IP, 1.16 WHIP, 2.59 BB/9, 7.83 K/9
2005: 2.30 ERA, 215 IP, 1.03 WHIP, 2.05 BB/9, 9.46 K/9
2006: 2.13 ERA, 186 IP, 0.92 WHIP, 1.64 BB/9, 9.66 K/9

Averages: 2.40 ERA, 1.03 WHIP, 2.05 BB/9, 9.09 K/9

First 3 in MLB:

2007: 4.40 ERA, 205 IP, 1.32 WHIP, 3.52 BB/9, 8.84 K/9
2008: 2.90 ERA, 168 IP, 1.32 WHIP, 5.05 BB/9, 8.27 K/9
2010: 4.69 ERA, 154 IP, 1.37 WHIP, 4.33 BB/9, 7.79 K/9

Averages: 4.01 ERA, 1.33 WHIP, 4.24 BB/9, 8.35 K/9

Looking at Dice's last three years in Japan, and comparing them to what pitchers have done in MLB for the last three years, Dice's ERA and WHIP would have been best in the league, his BB and K rates would have both been in the top 10, putting him in line with the Halladays, Verlanders, Kershaws and Lincecum's of MLB. He was an excellent pitcher in Japan, in the three years leading up to his posting he was getting better in all the stats sampled here. It just never worked out, his ERA went up 67%, WHIP up 29%, his walk rate went up 107% and his K rate went down 8%. (note I removed his injury riddled 2009 and replaced it with 2010, in order to give a more meaningful sample.)

Hideo Nomo:

Last 3 years in Japanese Pacific League:

1992: 2.66 ERA, 217 IP, 1.23 WHIP, 4.86 BB/9, 9.47 K/9
1993: 3.70 ERA, 243 IP, 1.43 WHIP, 5.47 BB/9, 10.21 K/9
1994: 3.63 ERA, 114 IP, - WHIP, 6.79 BB/9, 9.95 K/9

Averages: 3.29 ERA, 1.34 WHIP (2 year), 5.50 BB/9, 9.88 K/9

First 3 years in MLB:

1995: 2.54 ERA, 191 IP, 1.06 WHIP, 3.67 BB/9, 11.10 K/9
1996: 3.19 ERA, 228 IP, 1.16 WHIP, 3.35 BB/9, 9.22 K/9
1997: 4.25 ERA, 207 IP, 1.37 WHIP, 3.99 BB/9, 10.11 K/9

Averages: 3.34 ERA, 1.19 WHIP, 3.66 BB/9, 10.09 K/9

I really don't know what to buy in these Nomo stats, were his walk rates really that bad? If they were, was he really that unhittable that his WHIP rates were that reasonable? The data is really old so I do question the integrity somewhat. He was very erratic his entire career, the 3 year comparisons work out pretty well, the only noticeable difference if the plummeting of his walk rate from an obscene number to one that is merely very high. ERA up 2%, WHIP down 11%, BB rate down 33%, K rate up 2%.

Hideki Irabu:

Last 3 years in Japanese Pacific League:

1994: 3.04 ERA, 207 IP, 1.27 WHIP, 4.08 BB/9, 10.37 K/9
1995: 2.53 ERA, 203 IP, 1.13 WHIP, 3.19 BB/9, 10.60 K/9
1996: 2.40 ERA, 157 IP, 1.06 WHIP, 3.38 BB/9, 9.55 K/9

Averages: 2.68 ERA, 1.16 WHIP, 3.57 BB/9, 10.22 K/9

First 3 years (2) in MLB:

1998: 4.06 ERA, 173 IP, 1.29 WHIP, 3.95 BB/9, 6.55 K/9
1999: 4.84 ERA, 169 IP, 1.33 WHIP, 2.44 BB/9, 7.07 K/9

Averages: 4.44 ERA, 1.31 WHIP, 3.20 BB/9, 6.81 K/9

Those are Irabu's only two remotely full years in MLB, he never got over 60 innings in any of his other 4 years. He walked a lot in Japan but struck out a ton, that did not translate to MLB. His ERA wet up 66%, WHIP up 13%, BB rate down 15% and his K rate down 33%. Of course, bad seasons be damned the Yankees won 2 rings with him anyway, sort of like what we did with Dice, maybe that's the key, hope they bomb.

Masato Yoshii:

Last 3 years in Japanese Central League:

1995: 3.12 ERA, 147 IP, - WHIP, 2.38 BB/9, 5.56 K/9
1996: 3.24 ERA, 180 IP, - WHIP, 2.35 BB/9, 7.24 K/9
1997: 2.99 ERA, 174 IP, - WHIP, 2.48 BB/9, 5.37 K/9

Averages: 3.12 ERA, 2.40 BB/9, 6.10 K/9

First 3 in MLB:

1998: 3.93 ERA, 172 IP, 1.28 WHIP, 2.78 BB/9, 6.13 K/9
1999: 4.40 ERA, 174 IP, 1.30 WHIP, 3.00 BB/9, 5.43 K/9
2000: 5.86 ERA, 167 IP, 1.52 WHIP, 2.85 BB/9, 4.73 K/9

Averages: 4.72 ERA, 1.36 WHIP, 2.88 BB/9, 5.44 K/9.

Yoshii apparently became very hittable once he came overseas, his peripherals worsened only slightly but his results changed quite a great deal, his ERA rose 51%, BB rate went up 20%, and his K rate went down 11%.

Kazuhisa Ishii:

Last 3 years in Japanese Central League:

1999: 4.80 ERA, 133 IP, 1.46 WHIP, 4.80 BB/9, 10.96 K/9
2000: 2.61 ERA, 183 IP, 1.15 WHIP, 3.59 BB/9, 10.33 K/9
2001: 3.39 ERA, 175 IP, 1.19 WHIP, 3.75 BB/9, 8.90 K/9

Averages: 3.48 ERA, 1.25 WHIP, 3.97 BB/9, 9.99 K/9

First 3 in MLB:

2002: 4.27 ERA, 154 IP, 1.58 WHIP, 6.19 BB/9, 8.36 K/9
2003: 3.86 ERA, 147 IP, 1.56 WHIP, 6.18 BB/9, 8.57 K/9
2004: 4.71 ERA, 172 IP, 1.47 WHIP, 5.13 BB/9, 5.18 K/9

Averages: 4.30 ERA, 1.53 WHIP, 5.80 BB/9, 7.27 K/9

Another starter with great K numbers and bad BB numbers that each got worse. ERA went up 24%, WHIP up 22%, BB rate up 46%, K rate down 27%.

Let's see, Kei Igawa reference here, was a starter but his 71.2 innings pitched really isn't enough for this study. His 6.66 career ML ERA says it all though.

Hiroki Kuroda:

Last 3 years in Japan Central League:

2005: 3.17 ERA, 213 IP, 1.06 WHIP, 1.78 BB/9, 6.98 K/9
2006: 1.85 ERA, 189 IP, 1.00 WHIP, 1.00 BB/9, 6.85 K/9
2007: 3.56 ERA, 180 IP, 1.21 WHIP, 2.10 BB/9, 6.16 K/9

Averages: 2.86 ERA, 1.09 WHIP, 1.63 BB/9, 6.68 K/9

First 3 in MLB:

2008: 3.73 ERA, 183 IP, 1.22 WHIP, 2.06 BB/9, 5.69 K/9
2009: 3.76 ERA, 117 IP, 1.14 WHIP, 1.84 BB/9, 6.67 K/9
2010: 3.39 ERA, 196 IP, 1.16 WHIP, 2.20 BB/9, 7.29 K/9

Averages: 3.60 ERA, 1.18 WHIP, 2.06 BB/9, 6.55 K/9

Kuroda has been a very effective MLB pitcher with his great control. He saw a 26% rise in ERA, 8% rise in WHIP, his BB rate went up 26% and his K rate went down 2%. However, his Japan stats were so good, that even the rise in numbers still made a great pitcher.

Kenshin Kawakami would be next, but he only has 2 seasons under his belt and one of them was injury shortened, he isn't a success story though, seeing all his numbers go down significantly.

Through these starters we've seen that ERA goes up about 39%, WHIP goes up about 12%, BB rates tend to go up 25% and K rates go down 13%. However, given the sample size of stats I was looking for , the sample size of cases isn't very large (and is finite consider the low number of Japanese league starting pitchers who have made it over).

Now let's look at Yu Darvish and how he's done in recent years:

2009: 1.73 ERA, 182 IP, 0.90 WHIP, 2.23 BB/9, 8.26 K/9
2010: 1.78 ERA, 202 IP, 1.01 WHIP, 2.09 BB/9, 9.89 K/9
2011: 1.44 ERA, 232 IP, 0.82 WHIP, 1.40 BB/9, 10.71 K/9

Averages: 1.64 ERA, 0.91 WHIP, 1.87 BB/9, 9.71 K/9

If you modify for MLB with the factors we've seen you get something like a 2.28 ERA, 1.02 WHIP, 2.34 BB/9 and a 8.45 K/9. Which would be something very much like Beckett's 2011 season. His rapid improvement in just about everything is definitely a good sign, I'd say it's great if we hadn't seen Dice do the same thing. For comparison Dice might have been expected to put up a line of: 3.36 ERA, 1.15 WHIP, 2.56 BB/9 and 7.91 K/9. I've been strongly against even thinking about posting for Darvish for a long time now, these projections push me a little towards the middle, the lesson of DiceK is still fresh though and it is impossible to project adaptation. My only other worry about Darvish is that he has a high workload on his arm in the last 3 years, in fact, more than any of these guys listed, Nomo is closest, short a couple dozen innings I believe.

Answer the poll and comment away, let me know if there are any glaring mistakes in here.

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