Only A Computer Could Do This Super Mario Bros. Trick—Until Now - Kotaku

The Super Mario Bros.

In 2018, speedrunner HappyLee used a computer assist to demonstrate a new method to shave a few frames off of Super Mario Bros.

The speedrunning community had assumed a full, perfect run of 4-2 using this “top clip” trick could never be performed by human means due to the sheer precision required, and luckily, it has since discovered alternate, easier methods for min-maxing 4-2.

This doesn’t sound like a lot, but it’s particularly important in world 4-2 because of a Super Mario Bros.

In Super Mario Bros., the program only checks for level completion every 21 frames.

Catching the first possible bus in level 4-2, as was first demonstrated by computer-assisted runs, is sometimes called “Lightning 4-2.” That’s why HappyLee’s computer-aided trick, in which Mario saves a few frames by clipping through the top block in level 4-2, made waves: It was another way for runners to beat the frame rule and theoretically catch that first bus.