Here's the 2nd part of the video I linked above - after doing his job defense helping Kemba on Bam, shifting to cover Buckets's cut, and closing out to Olynyk when Theis went to pick up Bam from Kemba, Gordon got the rebound after Kelly's miss, then called for a stagger screen with Kemba and Theis and found Theis with a bounce pass for an easy dunk. Again courtesy of Jared Weiss from the Athletic:
----------From the Athletic
On offense, he has brought the Celtics’ interchangeability back into play. He can grab a rebound off a miss and push in transition, then with a simple wave of the hand, jump-start the Boston offense.
The Celtics tend to run their stagger screen set “11” a handful of times a game. The play almost completely disappeared in Game 2, as the Celtics could hardly get into their playbook against the zone. The problem is that the play is usually run by Walker or Marcus Smart, as a speedy point guard is needed to get around all those screens and fly downhill. But in this moment, Hayward decided he wanted to run the play since he was already in position.
So he waved over Walker, of all people, to set the initial screen before Theis set the stagger screen at the top of the arc. Miami switched Theis’ man onto Hayward while Theis rolled down the lane. Hayward crossed over to drive middle, drew the triple team and threaded a chef’s kiss pocket pass for an easy Theis dunk.
There was no confusion about who was going to run the play. He was decisive and executed with purpose, even though it was his first 5-on-5 basketball in a month. Hayward’s calm and precision was taking over the game. The moment was monumental for this team, the make or break night of its season, and Hayward conquered it.https://theathletic.com/2079280/2020/09/20/gordon-hayward-celtics-game-3-win-heat/
Clearly Gordy's still a ways away from being the max player he was looking like he was for large parts of this season, his shooting is shaky and his conditioning isn't quite there - but in a series that is on a knife's edge any advantage counts, and even a 70% Gordy is better than anyone else on the bench we have. But he will need to be better in Game 4, and better again in Game 5 and 6.