There is a belief that Masahiro Tanaka will be posted this winter and that some lucky team will spend a fortune for the rights to negotiate with him and likely sign him for the 2014 season. For those unfamiliar, Tanaka is the latest thing out of the NPB and like Darvish before him, and Daisuke before him, is considered the best pitcher the league has produced yet.
Should the Red Sox be aggressive in bidding for him? This is a complicated question and requires examining quite a few factors that have little to do with Tanaka directly. The most relevant one with many Sox fans is the fear that he will be another Daisuke.
That fear is understandable, but pretty well unfounded. Daisuke was actually nearly worth his contract for starters. I could point to fangraphs' value stat to argue that he was worth almost 45 million in his six years in Boston, but that stat is flawed in that it is derived of WAR which is a poor way to look at pitchers. I will point out that the bulk of his value was earned in his first two years, one of which ended in a World Series championship and the other in a trip to the ALCS.
So instead, I'll take a look at some other numbers and see how he stacks up. In 2007 he was 39th in FIP and 36th in xFIP. In 2008 he was 42nd in FIP, though he was 70th in xFIP. That makes him a solid number 2 pitcher while he was healthy and health is the main point here. If Tanaka is healthy, he'll be worth whatever contract he signs.
How do we determine if he'll be healthy or not? Well, we don't. There are far too many factors that go into whether a pitcher gets hurt or stays healthy in a season, never mind over a contract, but that's the case with every free agent pitcher. That said, there are some factors we can look at and innings pitched in the NPB is a good place to start. Tanaka has thrown 1268 innings in his career so far. Daisuke threw 1402 and 2/3 while in the NPB and Darvish threw 1268 and 1/3. Daisuke averaged 6.86 innings per game. Darvish averaged 7.59. Tanaka has averaged 7.55. So far he profiles a bit more like Darvish.
Both Darvish and Tanaka went deeper into games than Daisuke and it might have something to do with their builds. Daisuke was 6 feet tall and roughly 190 pounds. Darvish is 6'5 and about the same weight. Tanaka is 6'2 and 205 pounds. Daisuke was a bit small for a starting pitcher. Tanaka is smaller than Darvish, but not so much that you worry about the toil of a full season breaking him down the way we had to with Daisuke. He should be able to handle the work load a bit better.
That brings us to the question of what we can expect from Tanaka on the field. Here are the last three years of NPB production from each player.
Daisuke and Darvish both got stronger in each of their last three seasons, Tanaka appears to be regressing or declining. His previous four seasons were decidedly less exciting. Even so, his strikeout to walk ratio, even in his down final year, is right there in line with both Matsuzaka's and Darvish's best years. He has crazy good control and that will help him translate his success to the majors. Oh, and one more thing. Ben Badler from Baseball America thinks he might have the best splitter in the world. That link requires a login, but I'm not comfortable posting their content here, so it'll have to do.
I wouldn't be so bold as to suggest he will be on Darvish's level but I think there's a really good chance he's better than Daisuke was. For context, the best K/BB in the majors this year is Adam Wainright at 7.28 with Matt Harvey and Cliff Lee following at 6.16 and 5.86 respectively. Yu Darvish, even in the midst of a Cy Young worthy season, is at 3.88. Expecting more than a 4.00 K/BB from Tanaka when he comes stateside is probably going to leave you disappointed.
I'm comfortable guessing that Tanaka will be a better investment than Daisuke, so Sox fans shouldn't get too worked up about how that deal worked out. He'll probably come in well short of Darvish, however.
If that was all there was to it, I would probably be pretty insistent that the Red Sox bid hard for his services. I'm a fan and I want my team to put the best collection of talent on the field possible in any given year. That's not all there is to it, though, and several other factors need to be taken into account.
How much will they spend if they land Jose Dariel Abreu? How much will it cost to pay out arbitration raises? How much will they spend on re-signing Saltalamacchia or replacing him? Will they seek another outfielder or be content with a platoon between Nava and Gomes again? Will they spend on improving the bullpen? Will they try to re-sign Ellsbury now that there is a report that his starting price might be as low as 5/75? Do they want to add another starter to the mix in the first place, especially with six major league veterans and several prospects looking for a promotion?
All off this will need to be addressed before the team decides if they are going to bid aggressively for Tanaka. If they decide to go for it and win the bidding, I think Red Sox fans will be happy with what they get. He won't be another Daisuke, even if he's not the next Darvish. If they decide not to bid or to just offer a token bid to drive up the bids of other teams, I think there are several ways in which they can probably better spend that money.
Either way, Tanaka should make whatever team he signs with pretty happy.