John Wall’s most impressive play last weekend didn’t count. With 2.1 seconds left in the first half of the Wizards’ 107-102 loss to the Cleveland Cavaliers. Mo Williams had just made a layup when Wall tried to respond with a quick answer — a really quick answer — as he raced up the floor and dunked, needing just two dribbles. But the basket was called off because the ball was still in his hands as he elevated for the slam. He missed it by a half-second.