To make things a bit easier, select the Atlanta Hawks, turn off the fair trades option, then trade a few players to other teams. Trade for a better center (such as Ben Wallace), a better point guard (such as Gilbert Arenas) and a better power forward (such as Kenyon Martin). Then simulate the season and your team should win at least 50 games and the coach, Mike Woodson, will be the coach of the year. This is exactly what I did after simming several seasons with the Spurs and not winning the award to get the achievement.