The Main Event, an arcade game available in 2 and 4 player versions, is likely a sports-themed title possibly focusing on boxing or wrestling. The different versions (X, F, Y) may denote variations in gameplay, number of players, or cabinet configurations.  Without specific details on the game's content, the exact nature of these differences remains unclear.  Further research would clarify the game's developer and provide additional background.

The Main Event (2 Players ver. X)

The Legend of Silkroad (larger roms)