My assignment: Find the five biggest post-deadline trades of the last five seasons. Thanks to Retrosheet it was easy to find the trades. What wasn't so easy, though, was finding big trades. As it turns out, while there's plenty of talk about post-July 31 deals that change the fundamental dynamics of pennant races, in practice there just aren't many big deals, and the big deals that occur usually don't do much to affect the final standings.
Here, though, are the five trades that either did make, or could have made, some sort of difference: