A lot of variables -- quality players, the health of those players, luck, the subjective eyes of referees, etc. -- go into determining who wins and loses playoff series, playoff games, and the final minutes and overtimes of those games.
How much do coaching strategy and players understanding that strategy contribute to the final outcome? Well, ultimately players have to convert, they have to make shots. The strategies? Those, at both ends of the court, are designed to maximize the probability that those shots indeed will be made.
Want to know why Gregg Popovich is the best coach in the NBA? Because the Spurs carry out his late-game strategies and more often than any other team come up with a shot that, given the circumstances (i.e., an opponent that is trying to stop them), is the highest possible probability. On defense, the Spurs do whatever they can to make an opponent's shot the lowest possible probability.
Consider this scenario: Tie game, 15 seconds to go, teams coming out of a timeout. Team A is on offense and diagramming a play to get itself the best shot it can. Team B is on defense and devising a strategy to force Team A into the lowest-percentage shot possible. Hypothetically, in all of these situations, let's say Team A scores 35 percent of the time. When the ball is inbounded, players move into their sets. Eventually, when a shot is taken, we could take a snapshot of that moment: who is taking the shot, from which spot on the court, open or contested, etc. We would instantly know whether or not the probability of making the shot in that situation was greater or less than 35 percent. If it's greater, we could say Team A's strategy and execution won out. If it's less, we could say Team B's strategy and execution won out. This has nothing to do with the shot going in or not. That's up to the players. Hey, sometimes you make them. Sometimes you don't. But the goal of both teams should be to give themselves the best odds of being successful on that shot.
Let's take a look at the defining moments of the double-OT Game 1 between the Spurs and Suns. With the Spurs down three, trying to tie the game, they came out of a timeout and ran Michael Finley off a double screen along the baseline for a catch-and-shoot 3-pointer. Yes, Finley made the shot. But the Spurs perfectly executed the play they drew up. Finley is their best shooter for that play. They maximized the probability of converting in that situation. The Suns' defense, meanwhile, did nothing to run San Antonio off that shot. Leandro Barbosa trailed the screens the entire way. Amare Stoudemire didn't show to help. And the Suns didn't elect to foul either.
Now, with the game tied, the Suns had the opportunity to win, 15 seconds left. Steve Nash, with Bruce Bowen on him, dribbled the clock down, took a screen from Boris Diaw, but was partially cut off on a show by Fabricio Oberto, kicked it back to Barbosa, who was closed out by Tony Parker and forced to take a leaning, off-balance, contested 14-footer. There aren't too many shots in that situation that could have been worse for Phoenix. Regardless of whether or not it was poor Suns offense of great Spurs defense, San Antonio won that scenario, forcing the Suns into one of the lowest probability shots possible.
The offenses of both teams were sharp in the overtime, repeatedly getting high-percentage shots. Nash was more aggressive, didn't give up the ball easily or often (except for when he had Stoudemire for layups), and looked for his shot. The Spurs, meanwhile, ran screen-and-rolls with Parker and Duncan or Ginobili and Duncan nearly every possession.
Then, with three seconds left in overtime, tie game, Phoenix, once again had an opportunity to win. Their sideline out-of-bounds play from the frontcourt resulted in a direct pass to Diaw on the block extended, who first traveled (not called), then threw up an awkward, off-balance fadeaway that had almost no chance. If this indeed was the play Phoenix wanted, then Mike D'Antoni needs to be questioned. Three seconds is plenty of time for Nash to get something burning to the hoop and create space for a jumper. Anything but Diaw on the block that far from the basket. Once again, a very low percentage shot.
In the second overtime, again offensive execution was sharp. The Suns ran a great out-of-bounds play to get Nash free for the game-tying 3-pointer, but then poor defensive strategy hurt Phoenix one final time. The Spurs didn't call a timeout, instead electing to play on. Amid all the chaos, Ginobili got the ball in a 1-4 set, while the other four Spurs immediately positioned themselves around the perimeter. With the middle open, Ginobili began his dart about 45 feet from the basket. He drove hard left on Raja Bell and scored over the top. No help came, no double, no trap. The Spurs ran the highest-percentage play they could possibly run in that situation, and the Suns did nothing defensively to stop them from doing it.
Yes, the players have to make the shots. The strategies and executing the strategies, however, determine the probabilities whether or not those shots go in. More often than not the Spurs, at both ends of the floor, give themselves the best probabilities of converting. Are they perfect? Certainly not. But do they execute and play the probability game better than their opponents? Yes.
And this mind-set is a combination of getting the right players, who put in the work, understand the scouting reports as well as their own skills and abilities, and respect their coaches enough to do it. This starts in training camp, year after year. It cannot be flipped on like switch in April.
Once again, there are many variables that go into winning and losing games. This illustrates the part that coaching strategies and carrying out those strategies play in pushing single-play probability into or out of (albeit slightly, at times) a team's favor.