This could be pretty unviable in max difficulty runs, but it could save a lot of time on novice or 100% novice runs. It also makes the runs very reset heavy, as you will require The Pit or Dead Pool stages for this strategy to work.

Pick Sub-Zero as your champion, and what you will need to do is the following button combination: 1 1 3 B2 B2 1 2 4 CS 1 2 CS

This will knock the opponent off the stage before they hit 0 HP, making fights slightly faster. This also works on leaders, so this strategy is very useful against them