I've got NHL 91 and NHL 98 working on Dr Md.
Previously i couldnt get them working on the other Megadrive emulator.
Must be several rom versions out there. I previously couldnt get Madden 93 working on Rylehs Genesis emulator, always finished the game after the 1Q. Despite the rom being corrupt (has [c] in file name) its the only version i can find. However it works fine on Dr MD, weird !