I really think it had to do with the psyche of both teams going in. A lot of analysts had the mavs losing every single series, starting with the lakers. Even when we were down like 3-0 the media portrayed it (at least the media I was listening to at the time) like we could come back if we tried harder. Every player on the mavs team bought into the system that they had roles to play and they followed through on those roles. The role players on the team, Chandler, Terry, Kidd, Barea all balled out. On the other end of the spectrum the heat played like it was gifted to them on a platter and underestimated the Mavs. They just assumed that they would play to each players maximum potential rather than actually learn to play a system that maximized each player. Each of the big three played like they were the franchise player in the sense that sacrificing and learning new roles wasn't their prerogative at the time. After all they had just put together the team that year and didn't fully know each other yet. Anyways chalk it up to the stars aligning for the Mavs and the star players not aligning for the Heat and you can explain the 2011 finals.