An analysis of the effect of mid-season trades on team performance in the National Basketball Association

One of the most important duties of a sports manager is ensuring a team keeps winning to the best of its ability. If a team is performing poorly, the manager will typically take action to try and remedy the situation, usually through coaching/administrative changes or player trades. The more we can understand how these actions affect a team’s performance, the better we as managers can work to help our teams. Thus the purpose of this research was to gain a greater understanding of how mid-season player trades affect a team’s performance. Using simple statistical testing over a five-year period encompassing the 2010-11 season to the 2014-15 season, data was collected from all thirty teams each season to determine rates of improvement, decline, or no change in team performance following a trade. Comparisons were also made between the teams that participated in a significant trade and those that did not. Of the forty-seven NBA teams that had a trade, four were determined to have improved following their trade while one team was found to have declined. Of the ninety-five NBA teams that did not meet the requirements for a trade, five were determined to have improved after the trade deadline and five were determined to have declined. Overall, it was determined that there was no statistically significant difference in these rates of improvement, decline, or no change between the trade and non-trade teams. As such it seems that the only generalization that can be made about trading is that it likely will not affect team performance. Likewise, not trading typically will not affect team performance.