Super Mario Bros. speedruns are almost as perfect as humanly possible. The swift sprint through the Mushroom Kingdom has only seen incremental gains over the last few years, with runners besting times by fractions of a second. Runs of the game have become so optimized that it seemed impossible to do any better. Last night, a speedrunner pushed the game even further with a new world record run.

Kosmic is a Super Mario Bros. speedrunner who has held the world record multiple times. During a run last night, he beat the game with a time of 4:56.462, beating the previous world record held by Darbian by a mere four frames. It is an improvement of 66 milliseconds.

“I’ve been at world record level in this game since 2013, and I’ve never cleanly got it,” Kosmic said on Twitch after the run. “So I really hope no one beats this in three days. Not that I don’t expect it to never be beaten because that will definitely happen, but give me a little more than three days please.”

Prior to this, the world record stood in place for three years before runners like Kosmic and Darbian began to push records down further and further in 2016. A major cause for the shakeup was the use of the “flagpole glitch,” a trick that allows runners to grab the end of level flagpoles from inside the block they are resting on, saving valuable frames throughout the run. Combined with highly-practiced movements, it saw runners beating each other by as little as one frame, a time difference of one sixtieth of a second. These incredibly close runs led some to wonder if it was even possible to push the record lower.

Much of Kosmic’s time can be attributed to an amazingly fast run through the game’s final world, 8-4. Among the tricks required is a “wall-jump pixel.” When Mario jumps into a wall, he actually stands in the wall for a single frame. It is possible to time a jump when Mario hits that pixel. In 8-4, this is used to leap up to a pipe without using a hidden block. Kosmic’s 8-4 is one of the fastest achieved during a record run. It helped counterbalance the one frame lost during world 8-2 where he got a “lag frame” while attempting to use a bullet bill to push into the flagpole.

It is still possible to save time in Super Mario Bros. A faster use of a warp pipe in world 1-2 and “frame rule” manipulation in 8-3, which allows Mario to wait less time at the end of a level, could save valuable milliseconds. These tricks are highly precise but still possible. But a run incorporating them along with all of Kosmic’s optimizations might be as low as any human can ever hope to achieve. Still, if there’s one thing to remember about Super Mario Bros. speedrunners, it’s to never say never when it comes to new records.