- Series Hub: Heat vs. Spurs
MIAMI — The most important play in a game isn’t always the one you remember most. Sometimes, it’s subtle and doesn’t even make the highlight reel. Sometimes, something as simple as a change in possession can be more important than a shot that does or doesn’t go in.
The NBA has a way to use analytics to figure out just which plays had the biggest impact on a close game. It’s a “leverage” model that was developed to evaluate and instruct referees by pointing out which calls or no-calls had the biggest impact on a game’s result.
Here’s the idea: At every point of a game, each team has a certain probability of winning. Putting the quality of each team to the side, when the game tips off, the home team has a 60 percent probability of winning and the road team has a 40 percent probability of winning. After the first basket, those numbers haven’t changed much. But if the home team is up 10 with the ball and five minutes to go in the fourth quarter, their win probability (WP) is obviously a lot greater than 60 percent.
So, by calculating win probability both before and after a play occurs, it can be determined just how important that play was. Score, possession and location are the factors. And obviously, plays in the last few minutes of the fourth quarter (or overtime) in a close game are more important than any others.
Using the league’s data model, we’ve determined the three most important plays of Game 2 of The Finals, an easy 103-84 win for the Miami Heat.
Because Game 2 was a blowout, the plays that made the biggest impact came late in the third quarter, with the outcome still in the balance…
3. +7.4 percent – Ray Allen drains a 3
The Heat were up just two when Manu Ginobili committed one of the Spurs’ 17 turnovers. LeBron James brought the ball up quickly and got the ball to Mario Chalmers, who made the extra pass to Allen for a wide-open three from the left wing with 2:25 left in the third.
The basket changed the Heat’s WP from 66.2 percent to 73.6 percent.
2. +7.6 percent – A three-point possession
With James in the post and the score tied, Tim Duncan got caught for a defensive three-second violation. Chalmers made the technical free throw, and on the ensuing play, Chris Bosh hit a tough bank shot to put Miami up 61-58 with 4:30 left in the third.
Before the possession, the Heat’s WP was 58.1 percent. After Bosh’s bucket, it was 65.7 percent.
1. +8.1 percent – Chalmers’ and-one
A minute after that three-point possession, the Spurs were back up one and the Heat’s WP was back down to 53.8 percent. But they got a pair of offensive rebounds and were inbounding the ball under their basket with 3:17 left.
Chalmers then went around a James screen at the elbow, drew a foul on Danny Green, and converted a lay-up and the free throw. The three-point play was the start of the Heat’s 33-5 game-changing run and changed their WP from 53.8 percent to 62.0 percent.