On Thursday night at TD Garden the NBA's apparently unstoppable winning streak meets the league' provably unstoppable offense, when the Boston Celtics host the Golden State Warriors. The Houston Rockets may yet have lots to say to that in opposition, but their defensive problems were exposed by the Raptors on Tuesday in an eye-opening 129-113 defeat at Toyota Center that snapped a six-game winning streak. It has to be a worry for the Rockets that James Harden can produce 38 points, 11 assists and six rebounds and still end up on the losing side—comprehensively so—against a very good, not-quite-great, team.