I did some math on Twitter, and came to the conclusion that... the trade is probably fine. Depends both on whether Dubon's value had peaked at a lower value than we thought, and what the Brewers think of Ray Black. If Dubon was shopped on the open market and was not valued at anything over a 45 OFP by other teams, the Brewers are taking a risk that Ray Black will be worth at least 1 WAR before he hits arbitration. That's not a huge risk. OTOH, if the Brewers sold low on Dubon to get Black, the Brewers must really think they can unlock Black. At a 50 OFP For Dubon, Black would have to either be worth 2.5 WAR before arbitration (extraordinarily unlikely), or the Brewers plan on holding onto him into arbitration (more than a few years). We'll probably never know if they sold lower than necessary on Dubon, though, and there is some evidence to suggest that a 45 OFP was the proper valuation.