Can Pirates, Nationals hold on?

Behind Andrew McCutchen, the Pittsburgh Pirates are having a terrific season. Doug James/Icon SMI

Independence Day is most commonly associated with fireworks, going swimming, overcooking hamburgers on the grill, and, if you're like me, imagining the dollars flying out of your wallet as you watch your central air labor in 100-degree heat. When it comes to baseball, July 4 also represents the unofficial beginning of the busy trade season in major league baseball, the sport's equivalent of the mall on Black Friday.

The trade deadline makes July the crucial decision-making month of the season for most teams. It's the last chance to acquire the most coveted veterans or prospects and the point at which teams in the middle need to commit to a direction. So, on a general basis, when is the tipping point for the division during the season, the point at which the team leading becomes the clear favorite?