Nakajima isn't anywhere CLOSE to being the 2nd best hitter in Japan. Hes somewhere in the top 20-25.
I think what hes trying to say is that Nakajima is the 2nd best overall position player prospect in Japan. THAT might be true. There a tons of guys who could be slightly below average in the MLB, but very few potential above-average regulars right now.
All the stars are on the mount these days.
I do like Nakajima's chances of WAR'ing around 3 for 2-3 years, but he I wouldn't overstate his status as a hitter in Japan. He hits it a pretty decent hitter's park and I can't recall his OPS ever ranking in the top 10.

That said, the Ms should absolutely consider Nakajima. Matsui was such a bust, that I think Nakajima could come real cheap and the Ms have an enormous hole at SS for the next several years.
His bat should be league-average or slightly bettter. I'm interested in his glove. His range is probably slightly below-average, but the arm is above-average.
Overall I'd guess he'd fit somewhere in the 2.5-3.5 WAR range depending on how the D translates.
Guess how many 2.5+ WAR SS there were in the AL this season? TWO!
SS is a thin position these days and Nakajima is potentially one of the best SS in the league and cheap.

That Safeco beat Beltre and Sexson, as far as Sexson goes, he was out of baseball months after leaving Seattle, and Beltre, while his home run power did slip away in '09, he also spent most of the year with bone spurs in his shoulder.
Also, the more I look at Kazuo Matsui, the less inclined I am to see him as a pure bust.  In terms of what the Mets actually got for their money, absolutely, but in terms of his ability to play American baseball, I think there are caveats.  I notice looking at his stats, that Kaz only played 100 games in a season 3 times in his 6 (7 if you count this year) American seasons.  Looking at his injury record, yep, a back strain finished his first American season, and injuries to each knee hampered his next 2 seasons.  When he was finally somewhere near healthy, he put up good seasons for (post-humidore) Colorado and Houston.  Had he actually managed to play a decent shortstop, he actually would have ended up being a decently valuable player.  The fact that Matsui was a speed player that had multiple injuries to his ankles, knees, and back is what kept him from being a minor star.  The point here is, if Nakajima is the exact same hitter as Matsui, that's not necessarily a bad thing if he can stay healthy.
Moving back toward the subject at hand, I think Nakajima would probably be a good fit for Safeco, in that he seems to be more of a line drive hitter as opposed to attempting to loft the ball.  At least that's how he's often referred to, and the fact that he's hit into double digit double plays and his lack of extrabase hits compared to Matsui also point in that direction (there are other factors as well, Seibu's game has moved away from the way it was when Matsui was there, where he sac bunted 87 times in his career, Nakajima has done so only 7.  Matsui is also probably Ichiro fast as his sterling 83% MLB steal success rate can attest whereas Nakajima looks to be only above average.)
I actually like the idea of acquiring Nakajima a little more now than when I brought it up the other day.  Another thought that hasn't been brought up yet is the fact that on the Mariners, Nakajima would be playing with THE Ichiro.  This is a many sided opportunity, certainly there's likely to be a morale boost for Nakajima (similar to the one which Ichiro experienced playing with Ken Griffey Jr. last season).  There's also the smooth landing of playing on a team where you can get the opinion's of one of the games best hitters without the filter of a translator. That might be one of the reasons for Johjima's relatively smooth offensive transition into the majors.

He was 7th in his league in 2009, and tied for 12th overall

Thats a good point on the injuries.
In '07 and '08 Matsui was actually a slightly better than league-average player.
Even so, you'd have to consider him a dissapointment. I think Matsui's eye and K% were beyond the break-even point in the NPB.
Nakajima IS a line drive hitter and has decent gap power (especially for a SS). He shouldn't suffer as much as some of these other RHs.

Like I said, if he had played a decent shortstop, or if he hadn't been an especially frail player, I don't think he would have been considered a flop, but he would have had to do both those things to be considered a success.

You're looking at only Pacific League numbers. Including Cental League numbers:
2009: 13th
2010: Where did you find the data for this year? Hes likely around the late teens or early 20s this year if hes 12th in the PL.
So his raw OPS has been closer to around the 15-20 top hitters the past couple years. Considering park though, I'd rank him 20-25.

Is about what I would expect in terms of batting-wise.

The defense was dissapointing and really something that was difficult to predict since the tools were there. I guess he was just too used to the turf and couldn't adjust.
The offense was slightly dissapointing too, but in hindsight the eye and K% should have probably tempered our expectations.
Good point though. Without the injuries he probably would have still been an above-average 2B.

This one website had his stats for this season, his OPS was about .895 by my estimation.  And like I said, he was tied for 12th with Alex Ramirez between both leagues last season. 
And wouldn't he get a little bit of credit for playing shortstop?  Don't most players gain 25-50 OPS points if they move off of shortstop (in their primes that is)

Have you read a study on that?
I checked the Japanese site. Nakajima was 14th overall this year in OPS, although there were several guys in the 880 OPS range in more neutral parks.
Even so, perhaps 20-25 was too harsh. 15-20 range seems more accurate adjusting for park.

I think he does a little better, but thats a good downside scenario.
He probably hits around .280+, with around 0.70 patience, so OBP around .350. My guess is an IsoP around .120 if hes in Safeco.
.280/.350/.400 would be my guess. Hes the SS version of a prime-Iwamura minus some Ks and BBs and maybe a few more doubles.

Great breakdown, Doc.
 
For me, it looks like this:
Benefits:
 
- Able to replace black hole at SS (62 OPS+ from Jack Wilson since the trade, 68 OPS+ from Josh) with a decent hitter, which as you say is like replacing a decent player with a superstar. This is the same reason I would look hard at an offensive catcher and would find out about raising payroll to add a V-Mart. In his down year he posted an OPS+ of 122. Moore was 44, Johnson 63 and Bard 77. If you could get me Nakajima and just a 90 OPS+ at SS and 110 out of V-Mart we'd be adding a ton of runs. Victor won't be coming here, I don't think, but Nakajima is gettable if they post him.
 
- Theoretical ability to add payroll for Japanese players is undeniably helpful. If we're on a strict American budget but can flex for Japanese players out of our special "Land Of The Rising Sun" fund, then Nakajima is basically a free acquisition. He wouldn't necessarily be free to keep (nobody's been able to figure out if we really are adding payroll for the Johjimas of the world or if they fit into the hard budget once they get here) but if that flex fund helps offset dumping Jack Wilson for a better option, I'm all for it.
 
- SS is a tough, tough market right now and there aren't a lot of good ones. Being able to add a decent SS in a tough market HAS to be considered a good get, especially if he's (relatively) cheap.
 
Drawbacks:
 
- all the stuff I listed earlier. Bad park for him, probably can't fire him if he sucks, blocks off a position for one of our top prospects (not that I make calls based on that cuz Franklin can still epic fail), new country, et al.
 
Is it worth it?
 
Two years of sub-70 OPS+ numbers from the position would make me contemplate using the Bearded Lady if she could OPS .750.
 
Nakajima is definitely an option - he's just not a slam dunk. Many, many things can go wrong with him. That said, Jack's not getting a year 4 if he loses 95+ again. He's GOT to fix the offense and do it without money AND while breaking in the new kids he plans to build the roster around.
 
Nick Franklin is not A-Rod. He can chill in the minors til 2013 or 14, and might actually need to. In the meantime, Jack needs to fix the 2011 offense NOW, or Franklin's potential success will be some other GM's claim to fame.
 
Give Nakajima a call.
 
~G

After about a year of time out I managed  to come here.
There is a discussion of whether Nakajima is 2 WAR or 3War.
I would say Nakajima is 4WAR if Figgins and Nakajima will compete for #2 spot (looser get #9 spot) under a strong manager like Valentine.
(but the 1WAR comes from Figgins)

It's just an intuitive thing; shortstop is hard on the body, if you play a less physically demanding position, then it translates to improvement in other areas.

Either the stress of being righty is so bad that it crushes your career no matter where you play (Sexson) or it only crushes you as long as you play in Safeco (Beltre).  Certainly the park hurt Beltre, I'm just saying it didn't psychologically cripple him.  Beltre's 2007 would have been a near-MVP caliber year as well if the beginning of the bone spurs that would hinder his 2008 and ruin his 2009 hadn't creapt up in September (If I remember correctly, he was originally diagnosed with tendonitis and wasn't rediagnosed with bone spurs until he would have to miss a large chunk of 2008 with surgery, so he put off the surgery until late September 2008).  He was batting .282/.329/.503 through September 11th that year.  He would finish the year batting .236/.258/.350 with 17 Ks to 2 BBs over his final 82 plate appearances.  Still, his season line that year included 41 doubles and 26 home runs in about the same number of plate appearances this year.

Ichiro made clear that his 40+ SB in 2010 was because Figgins hit #2.
He said Figgins did not make a foul at bat when he took for 2nd base. In 2010 he had many fouls from Beltre.
Something cyber-friends should find out...
That Ichiro could not score in 2010 with his OBP and SB is another story.

Zduriencik, you would think, would indeed be pulling out all the stops -- perhaps including Bobby Valentine .... perhaps your V-Mart type move... and how does he fix SS if *not* Nakajima?

 
This is actually a concern of mine.  We can't - CANNOT - rely only on the kids all working out to fix us.  Bavasi was a terrible judge of player ability and he left us with very little immediately usable talent.  I find myself doubting Saunders and Moore simply because Bavasi chose them and hung on to them.
But regardless, nobody wins with an entire roster of first and second year players, and some dirt-scrubs and last-year vets to fill out the back end.  I'm pretty sure we proved that this year. 
Which means Jack needs to spend his cash, whatever of it he's given, wisely.  There is zero veteran leadership on this team.  There are zero vet power bats for the MOTO.  He's gonna have to find some.  Pat Burrell is getting big props in SF for growing up and taking control of that clubhouse.  We need a vet like that.
But we saw what happens when a GM HAS to make a splash.  Bavasi did it once with Beltre and Sexson, and again with Bedard.  I am at least comforted that Zdurienczik seems free-spending with the prospects he believes are not stars - and that he's been proven right a lot of the time.
I just worry that the need to add quality players might add more Figginses that we don't need, or more Sexson-like contracts.  Jack gets to show us what he's learned about adding major league players this year.  He's been good with judging the minor leaguers, and with the can't-miss Cliff Lee types, but we need quality vets who can play a full season as an above-average bat, and so far Jack has come up with exactly none of those for the lineup.
We need at least two to have a chance.
I wish him luck.  If Nakajima is one he's definitely not gonna be leading the locker room in anything but he might be able to boost us a large amount on the field, which is one of our two problems.
They say winning cures all ills.  I'd like us to prove that.
~G

AND hire a manager who will run the clubhouse and the media (like Valentine) he might get out of this scenario with his job intact - and we might get to set up for some serious winning down the line.  We don't necessarily need a veteran player to set the tone, but somebody has to.  At least until Ackley and Smoak are ready to do so.
We'll see.
~G