Otherwise the answer is a healthy team, a tighter rotation, and the luck that every team needs to win 16 games in the real season.
Having the 6 years straight RealMVP (2002-07, probably 1999 also) as an anchor along with future HOFs Manu GNob and Tony Parker and others on a Championship team is hardly considered "luck". Toss in DRob for two titles, Bruce Bowen on lockdown D, Shaun Elliot when healthy, DRob as a role player big and guys like Brent Barrdog, TRex, Mario Ellie, Fabs Oberto 07 and SuperStevie Kerr as role player, heck even Findawg in 07.
The only "luck" involved is opponents having an idiot like Popped along with the 2003-onward Front Office to hold the Spurs back from taking 8 of 12. Certainly at least one repeat.
You talk about Swishers greasy .4 shot, how about Laker Big Shot Bob Horrys rim out to save Popazit from a 15 point lead collaspe that he orchastrated with his stand n veg offense. Should have never gotten to that point! Or the rigged call to rob Barrdog in 2008. Why did Popazit wait until game 4 to insert Barrdog instead of 60% GNob. The only "luck" was psuedo ZenPhil having Popped as an opponent.