Time-Is-Moneyball

There is a certain rhythm to a baseball season. It starts off in a mad rush, with small hot streaks by bad teams and unknown players exciting all sorts of cloud cuckoo-land extrapolation. (See: This April's Miami Marlins, and everyone who thought they'd win 100 games based on their first week).  Then it settles into the process of shaking itself out, as good teams separate from bad, and injuries knock off contenders without depth. Flashes in the pan fade out until everyone's got a pretty good idea of whether they're contenders or pretenders, and then the trade talk starts. This tends to be a ton of nothing until July, at which point trade talk starts bubbling up ahead of the July 31st deadline. 

It is, as they say, the way things done. Teams will wait until the last minute to be sure to extract the best possible deal for the pieces they're attempting to move, which means that acquiring teams get that much less of their new players, which in turn makes them that much less interested in surrendering quality for them, which kind of defeats the purpose of the whole thing, and, well, oy.