The Celtics have made a lot of bad decisions on the floor through the first four games of their series with the Knicks. They have thrown the ball to people wearing uniforms of a different color and they have thrown the ball to paying customers — who were, to be fair, open.

Before they take the court in New York tomorrow night, the Celts must make another decision. Do they want to make their own plans for Friday night, or would they rather the NBA tell them where to go?

The crew at TD Garden is holding the date open for them, and the Celtics’ first step toward filling it with a Game 6 is to come to the conclusion that they badly want their season to continue.

Of course, even then it may not matter.

The Knicks are still the more talented team, a fact proven rather conclusively while they’ve built a 3-1 lead. If the Celtics do not fly to New York today with a damn-the-odds belief in themselves and an insane desire to become the first NBA team to overcome a 3-0 deficit, then the charter will be little more than wasted fossil fuel. They cannot, however, focus that far ahead. Tomorrow’s choice is simple. Would you rather have Friday or summer?

The Celtics have already performed the face-saving task of avoiding the sweep. Now it’s about something more basic, something gleaned in the playground at an early age.

This is about keeping the court. If the Celts win, they get to stay — albeit with a move back to their parquet park. If the Celts lose, they have to wait until next season to run it back.