Usually it takes years before we can fully evaluate the success of an NBA transaction. More than any other sport, the participants in an NBA trade have completely different motivations for the swap. Generally, one team is looking for a short-term boost, while the other is trying to clear cap space for longer-term gains. It's might not be quite as cut-and-dried as that, but most NBA trades fall into those general categories, especially when they occur within the season, when some teams are gearing up for a postseason run and others are looking further down the line.
This season, we saw an unusual in-season trade when Memphis sent leading scorer Rudy Gay to Toronto in a three-team deal that brought veteran forward Tayshaun Prince to the Grizzlies. At the time, critics of the deal thought it was criminal for Memphis to give up on a season when the Grizzlies were dancing on the perimeter of the championship derby. Meanwhile, the brass in Memphis insisted that not only were they freeing up roster flexibility for the future, but that the deal was improving the team for the short run as well.
As we've seen, the Grizzlies nailed the deal from a short-term perspective. They got better immediately after dealing Gay, won a franchise-record 56 games and hang on the cusp of a berth in the Western Conference finals. Right now, it looks like the trade of the year, at least in terms of postseason impact, serving not as the death knell of Memphis' playoff chances, but rather the catalyst for a deep run.
What other in-season transactions have affected the playoffs? Here's a list of the major ones, ranked subjectively, though I've cited the playoff WARP totals -- wins above replacement player -- for the principle characters in each acquisition.
Forget the WARP figure. Prince has fit in so well for Memphis because of who he is not. His presence has allowed the Grizzlies to redistribute possessions to Zach Randolph, Marc Gasol and Mike Conley, while Jerryd Bayless has become more of a factor on the perimeter. Prince also has held up on the defensive end, teaming with Tony Allen to help keep Kevin Durant under relative control in the team's second-round series versus Oklahoma City. Memphis' decision to deal Gay, the most debated in-season transaction of the 2012-13 campaign, has served as the springboard to position Memphis for its first berth in the conference finals.