A grade is the model's value read at the time, as a letter: how far apart the two packages were after package counting, as a share of the larger one. Trades the headline calls fair are a B for both clubs. It leaves out cap, lineup holes, fit, the contention window and injuries, which are listed separately below, and a club can take a lower grade for need. It's not a prediction of who wins the trade; the value model ordered real trades only modestly better than chance.