[...] the first round of the NBA playoffs has been a bit of a dud, with three sweeps already in the books and the Grizzlies, Bulls and Rockets entering Monday with comfortable 3-1 leads. Thankfully, the Spurs and Clippers are throwing haymakers at each other the way most expected when the series began. The Rockets host the Mavericks in the other game Tuesday night, needing a win to get the series back home to Dallas for a Game 6. The Clippers and Spurs have traded victories, with each team responding so emphatically after a defeat that no feasible momentum has been established either way. Both teams are playing with a welcome edge in this series, having already experienced how thin the margin for error can be. Mavericks at Rockets, Houston leads 3-1, 8 p.m., TNT Clinging to their playoff lives in Game 4, the Mavericks called on the two most obvious candidates to keep them in the series — Al-Farouq Aminu and J.J.