The fight for the first-ever perfect Super Mario Bros. speedrun is getting serious. This week, speedrunner Niftski set a new world record that is just four frames shy of what’s believed to be the fastest possible time achievable in the NES game.

Super Mario Bros’s speedrunning scene has been on fire in the past year. Players have gradually chipped away at it to the point that world records are now only a matter of frames, not seconds. Last week, speedrunner Kosmic posted a YouTube video detailing the game’s previous record, a run set by player LeKukie that was just six frames short of perfection. That has now been annihilated by Niftski, a former world record holder who has reclaimed the throne.

Niftski’s run clocked in at 4:54.332, which shaved exactly two frames off of LeKukie’s record. It’s an astonishing feat, but the finer details of it are hard to comprehend without knowledge of speedrunning tricks. Niftski nails almost every single pixel-perfect technique in the book, including backwards-jumping fast acceleration. The only thing holding him back from perfection was the final level, 8-4, where he lost four frames to a mistimed pipe entry, a too-high jump, and a skipped acceleration boost in the final room.

Even more impressive is that he didn’t pass out during it. Niftski includes a live heart rate counter on his screen while streaming. During the run, his heart rate got as high as 176. When he finished the run, it spiked to 191 during a celebratory pop-off. His audience was seemingly so concerned about it that Niftski dedicated a paragraph in the description of the YouTube VOD of the run confirming that he does not have a heart condition.

It’s an especially meaningful moment for Niftski, because he has been at the center of a controversy in the Super Mario Bros. speedrunning community in recent months. Niftski plays an emulated version of the game, which he controls mostly on keyboard, but switches to a controller to complete 8-4. That control-switching method was briefly deemed illegal by the community earlier this year. The decision was reversed last month after further community feedback, though with some new ground rules.

Niftski maintains that there is no advantage to using a keyboard for playing Super Mario Bros. (“It is actually debatably worse for speedrunning this game,” he wrote in the description of the world record YouTube video.) While that is largely agreed upon by community members that have dug into the hard data, there are players out there who believe that keyboards aren’t in the spirit of the run. All that really means is that there will likely be another race for someone to achieve a perfect run on a "proper" NES one day.

For now, the countdown to the inevitable is on. Whether it's LeKukie, Niftski, or someone else entirely, someone is bound to crack the perfect playthrough soon enough. Hopefully their heart survives the feat.