The NBA is a copycat league. When teams advance deep into the playoffs, their rivals study their success to see what strategies can be stolen. When teams fall flat, opponents see what approaches to avoid.

After a particularly hectic year of trades and free agent signings, let's examine what the league might have learned about how to construct a winning roster. The upcoming postseason might change views, of course, but many of the most important transactions from last summer and the trade deadline have already borne fruit, one way or the other.

Here are eight lessons from the past year of transactions, for all the teams trying to improve this summer.

1. Don't trade a 25-year-old generational superstar with no warning

This lesson seems as if it should be self-evident, but apparently, it needed to be learned through experience.