Among the coaches who have served more than 2 NBA teams, during which coach's period of coaching, a team has the least numbers of games lost in the post-season games?
served more than 2 NBA teams refers to count (tmID) > = 2; least number of game lost in post season refers to Min(post_losses)
SELECT coachID FROM coaches WHERE lgID = 'NBA' AND post_wins != 0 AND post_losses != 0 AND coachID IN ( SELECT coachID FROM coaches WHERE lgID = 'NBA' GROUP BY coachID HAVING COUNT(tmID) > 2 ) ORDER BY post_losses ASC LIMIT 1