Here is an excerpt from a general baseball chat by Jay Jaffe at Baseball Prospectus:
Scott (DC): If the Reds find a huge pile of money under the mattress and add Johnny Damon, do they instantly become favorites for the Wild Card?
Jay Jaffe: Man, if the Reds understood anything about the marginal win curve, they'd already have signed Damon. He'd be a nice fit in that park, and they really could use his bat atop that lineup.
Then again, that they haven't signed him suggests that maybe they know too much about the conditions of some of those young arms. Say a prayer for Johnny Cueto and Edinson Volquez tonight.
Marginal win curve basically means that the value of a win that takes you from win 84 to win 85, when the wild card winner is 85 wins, is a lot higher than the value of a win that takes you from 70 to 71 (or for that matter from 102 to 103). Teams that are very close to contention should pay a lot to get extra wins. Teams that are out of it need not worry and teams that are locks shouldn't over pay for more wins. (That's some what simplified for the locks, because they may be simply improving the team for a playoff win, and those are very valuable.) If the value of Damon is three wins, that would be very valuable to a team like the Reds, but not as valuable to a team like the Pirates.
Having said that, Damon is the perfect fit for the Reds because the Reds desperately need a left fielder, really their one remaining question mark. I guess it still remains to be seen what he'd be willing to take, but I still say he could be this year's Abreu although I've said that about Jermaine Dye, as well. Maybe the answer is to see which one of those two would play for the smallest salary and sign that guy.
Having signed some veterans like O-Cab and Hernandez, and extending Rolen, is wasted money unless the Reds are trying to win. The marginal value of adding one more piece is huge and the Reds should not let this chance go to waste.
Here's a fun scenario: The Reds sign Damon to a one-year, $6 mil. deal. The great Winn/Thames/Gardner experiment fails miserably, and the Reds trade Damon to the Yanks for catching prospect Jesus Montero. That would be nice for everyone but the Blue Sox.