1) A mix between Tabula gammon and Russian Gammon. Basically like "race", all pieces start off the board - BOTH players race the same direction around the board, bring in their pieces in the same area - can only move their pieces 1/2 way around the board until all of their pieces have entered the board - 2 dice only - no special double rules - rest of the rules like current gammon/race rules.
2) Domino-Gammon - I have since seen some other versions talked about, but linked are the rules that I have made up for the game.