[dfxm12]

No game is perfectly balanced & no players are perfectly balanced either. I don't know about mortal kombat, but home versions of games had handicap features built in for situations like this. You can also do some out of game handicaps like "I get one free move" or "you can't use this special move".

If nothing else, the variety keeps things interesting.

[SliceOfWaifu]

There is a difference between balance and ignorance. Handicaps don't work very well if one player has stronger fundamentals than the other. It'll just be a slippery slope of stacking handicaps until one player ragequits. Instead of trying to Harrison Bergeron the situation, your best bet is to just play a different game or find a way to motivate the other player to learn as you did.