I'm sure it is very good. But not perfect, how could it be? And I think there are impacts a player can have that don't show up on a stat sheet anyway. Not just intangibles, but how other players in the lineup are affected, how opposing players pitch to them, how many risks the manager takes, etc. He cements that lineup. Removing Cabrera from that Tigers lineup would leave such a massive void, I just think the loss of wins would be more than WAR would suggest. (caveat: pure opinion, but I think a fairly common one)