set up games to only allow one player games.
on newer games its an option, set it on free play, allow one player games only, done.
if its an older game:
Have it on money play and start with one credit (so no one has to actually insert money from the start).
-make a replay as low as possible winning one credit each time someone plays,
done.
yes, it sucks that you cant have 2,3,4 player battles, but if it helps with single players playing a 4 player game hogging games, so be it.