They're in common use in the NFL. And the NHL has a comparable sized draft (32 teams 7 rounds). I think they're in use as a guideline by some teams. For instance this minor trade in 2007. The Avs traded 3/91 to San Jose for 4/113, 5/143 and 6/170. 136 for 68+34.5+23.4=125.9.