Today's top sports stories:

The NFL has approved several rule changes for the upcoming season. Most prominently, the "tuck rule" has been abolished, along with new regulations against certain kinds of helmet hits and tweaks to coaches' usage of instant replay. [ESPN]

The Miami Heat take their 23-game winning streak to Cleveland tonight, where they'll face the Cavaliers, who have a record of 22-45. "Make that 24-game winning streak," said everyone. [S.I.]

Los Angeles Dodgers shortstop Hanley Ramirez could be out as long as two months after injuring his thumb during the World Baseball Classic. Or it could be just two weeks. Who can tell?!?!?!?! [Yahoo]

You may have heard that there's this little basketball tournament thing that starts on Thursday. Even President Obama has filled out a bracket, picking _______ to win it all. [ABC]

And if you want to really have fun watching the NCAA Tournament, check out this March Madness drinking game. (To be used with water and juice only, of course.) [GuySpeed]