) Mark Dondero (@MarkDondero) and Ben Kichen ponder what’s going on with the Celtics. Mark is not saying the Celtics can't convert on game winning shots. Do Jaylen Brown and Jayson Tatum have what it takes to win a championship? Brown and Tatum need to learn how to attack the rim. The Celtics haven’t been great in overtime. Brown is missing clutch free throws.