This past week, a bug was discovered in Mortal Kombat 1 that unintentionally gives whomever is Player 1 an unfair advantage over their competition. The issue is that Player 1 is able to pull off combos that are impossible for Player 2 to pull off. It doesn't matter which direction the player is facing, only that they be Player 1.
Obviously, this is a pretty severe issue for a fighting game that can be played competitively....