We have seen many instances of this over the years. Robert Parish was considered a troublemaker in Golden State they felt that he would never be a good center and couldn't wait to trade him so that they could draft Joe Barry Carroll, and yet became a Hall of Fame player in Boston. Dennis Johnson was considered a malcontent who couldn't run a team and became the glue that held the team together in Boston. Jermaine O'Neal was seen as a bust in Portland and became a dominant player in Indiana. Darko Milicic was a non-entity in Detroit only to become a player in Orlando. Steve Nash languished in Phoenix before breaking out in Dallas. And on and on.
There are instances throughout the NBA. A player seems washed up, a troublemaker, a mistake, etc. only to become an All Star on the team they are traded to. Chauncey Billips was a player seen by Rick Pitino as not developing quickly enough. But yet he went to Detroit and developed very quickly. The same can be said of Jermaine O'Neal after he went to Indiana.
In most cases, the difference is in the system or the coaching. Some come from a system that doesn't fit their playing style. Or the coach and the player don't get along and so the player is not given playing time or is given a reputation as a malcontent or lazy. Or, sometimes it is just the player maturing and breaking out that coincides with the trade. Sometimes it is the teammates that make a difference in that the chemistry is just right among a group of player or the chemistry doesn't work with others.
Sometimes, it is the player and not the system that is the problem. I had hoped that Telfair was one of those players who would blossom when given a fresh chance with a new team, but it didn't work out that way. Telfair may still break out and find a system where he can shine, but it didn't happen in Boston. Rondo came out of a system that didn't play to his strengths at Kentucky. Because of that, he had some adjustments to make when he came to the NBA. In spite of seeming to struggle in the Kentucky system., he came into the NBA and has become a very impressive point guard already with just 2 seasons in the NBA and led the Celtics to their first championship in 22 years.
There are also many cases where a coach is fired and the team does a turn around because the coach was not getting through to the players or the coach's system didn't fit his players. This is why we see so many coaching changes in the league. As there are trades and personnel changes on teams many times the coach's system no longer fits the the new players and a change has to be made. After spending a fortune to bring in highly paid players, it is usually the coach who goes and not the players. The Celtics made wholesale changes last season and the system and players fit together surprisingly quickly. The Celtics will have the same starting 5 next season to bring some continuity but the bench will be dramatically different. Their key reserve, James Posey is gone along with PJ Brown, Sam Cassell, Scot Pollard, and possibly Tony Allen and Eddie House. Patrick O'Bryant will be a new face and as the off season wears on, Danny will be adding other new faces to fill the gaps on the bench. Danny needs to carefully select the players who he feels will fit into the system and chemistry of the team. Any player not willing to buy into ubuntu should not be considered.
Patrick O'Bryant is another player who may have been the victim of being in the wrong system and with the wrong coach. Don Nelson is notorious for playing his veterans and not liking to play rookies or young players. His system is a run and gun type system and not one very well suited to a back to the basket type defensive player. In his 2 seasons with the Warriors, he played in 40 games and averages 1.7 points, 1.3 rebounds and .4 blocks per game. But, he also spent some time in the D-League and there he started to show some flashes of the promise that the Warriors saw when they made him the 9th pick in the draft. In '06-07 he played in 25 games for the Bakersfield Jam and averaged 12.0 points, 9.6 rebounds, and 2.9 blocks in 29.5 minutes per game. In the '07-08 season, he played in 8 games for the Jam and averaged 16.0 points, 10.1 rebounds and 3.5 blocks in 36 minutes per game. Those are encouraging statistics. It is possible, with the proper coaching (Clifford Ray) and the right system (the Celtics) and the right teammates to help him develop his work ethic (KG, Perk, Leon Powe), he might just surprise a lot of people this season.
There have also been reports of Stephon Marbury possibly coming to the Celtics. He has been called a cancer and a malcontent and has been blamed for a lot of the troubles the Knicks have been through in recent times. But, then again, he was playing in Isiah Thomas' system. It is possible that a change of system, a change of coaches, and a change of teammates may make all the difference in the world to make him a team player.
A lot of teams are making big changes this season with both players and coaches, but just because they make coaching changes or bring in a star or several new players, it doesn't mean that they will be greatly improved. It all depends on how the new players fit into the system and how they mesh as a team. The Celtics had perfect chemistry last season and it will remain to be seen how well the new players will mesh with the old and how much they will miss the players who are gone.