And yet Bautista has the highest WAR, doesn't he?
His and Pedroia's are essentially the same.
Could the 850 OPS player be more "valuable"? From the perspective of team composition, sure -- because the fall-off is greater to the next guy. But I think valuable is different from better. (I also might take the 850 OPS guy over the 1000 OPS guy because of contracts, for an analogy -- an 850 OPS guy at $1mm may be a better value than the 1000 OPS guy at $20mm --doesn't make him better, though.)
I'm not sure if I understand you correctly, but what I"m saying is that an 850 OPS CF is a better player than a 900OPs 1B, and by a wide margin. Any time you can find a player who can hit, and can play an elite defensive position, Its hugely valuable.
If you believe the Sabre crowd (and I do), a defensively average SS or CF is worth 10 runs more than an average defensive 1B. Thats mostly offset by the fact that an average 1B hits about 10 runs better than an average SS. Now, we can argue about what the exact numbers should be, but I don't think there's any way to argue that defense and positional scarcity are just as important as extra points of OPS. If that wasn't the case, we'd have guys who look like David Ortiz playing almost every position.
Jose Bautista is an awesome hitter, but your average corner OF has an OPS in the 820 range, and Bautista isn't an average corner OF, hes a bad one. His 1090 OPS is awesome, but every time he can't get to a ball because he has terrible range costs the jays runs. And those runs offset some of the value he provides with his bat.
Ellsbury, on the other hand, plays a position where almost everyone (except Granderson, who isn't nearly the defender Ellsburry is) has a noodle bat. He plays it really well too, and that helps teams win. His defense has been about 8 runs (and will be about 10 by the end of the season) better than the average CF. What that means is that Ellsbury, with his .880 or so OPS, provides just as much towards winning as an average defender in RF who has a 1.000 OPS.
Is he as good as Bautista? No, but
if his performance this year is what hes going to continue doing, he absolutely is one of the best players in the game. There are 5 CF in the game who can hit right now (Granderson, Ellsbury, Kemp, Victorino, and McCuthen). Kemp and Granderson are the best hitters, but they're worth the least because they both are bad defenders and should probably be playing on the corners. Granderson and Victorino are both on the wrong side of 30.