Miami beat you by 15 on the backboard and by 16 on the scoreboard in game 1. You can’t control how many of your own shots go through the net. You can control how you approach going after rebounds.
You don’t get fastbreak points anyway. There’s no point in leaking out after the Heat shoot the ball. Send the guards to the defensive boards.
The Heat are too much faster and more athletic. They are going to win a race to the ball most of the time. So commit to your team defense. Switch pick and rolls with KG and Bass if you think that’s best, but above all gang rebound.
Win at least one aspect of the game.