Upton could easily be a 6-7 win player and B.J. could top out at 5. Making up the difference right there.
Should be a great race!
Well yeah, BJ Upton COULD reach a level he's only reached once, 5 years ago, but it's more likely that the Braves lost a win moving from Bourn to him, considering their production over the past three years (<4 WAR per year for BJ vs. >5 WAR per year for Bourn).
And Justin Upton COULD reach a level he's also reached once, but it's also not the most likely scenario. I don't think he's a 3 win player, but I also don't think he's a sustainable 6 win player, unless he can produce 1.5 wins on a regular basis in the field and on the bases. He's topped out twice at .370/.530 and he's not on the steep upcurve of the improvement curve anymore, so it's unlikely that he's going to turn into a .400/.570 monster at this point. 4-5 wins sounds more likely, which might be a slight upgrade over Prado, but not a huge one.
The major win (I guess) is that the Braves have 2 more years of Upton, but considering they're paying him $13 million a season over those two years, it doesn't sound like a huge upgrade over Prado @ $10 million per, which is what he was asking for and the Braves were unwilling to pay.
In any case, it doesn't really matter, since I view the wildcard game as only a slightly bigger tossup than the DS. Both team teams were making the playoffs, before and after this trade.