Record-breaking Super Mario Bros. speedrun approaches robotic perfection

Back in 2021, when speedrunner Niftski became the first person to complete Super Mario Bros. in under 4:55, we used the four-minute mile as a metaphor for the difficulty and importance of the achievement. But now that Niftski has pushed that time even lower—setting a new world record of 4:54.631 for a live, human-controlled full game run—we’re left grasping for metaphors that accurately capture the performance.

Niftski’s new record perfectly matches a “perfect” TAS of the game (i.e. a “tool-assisted speedrun” that uses frame-by-frame input recordings using an emulator) through seven of the run’s eight levels. His best time is now running ahead of the “theory limit” of 4:54.798 that runner Bismuth set back in 2018 as the ideal human performance standard.

In the battle of man vs. machine, Niftski is now just 0.35 seconds away from standing up, John-Henry-style, against the standard of machine-made automation. Hey, I guess I did come up with a good metaphor after all.

“Lightning” in a bottle

Most of the tricks Niftski uses to shave off precious milliseconds in this new world record run will be well-known to speedrun fans and are outlined in our writeup of Niftski’s 2021 world record performance. The major breakthrough this time around, though, is a full-game run that integrates a “Lightning 4-2” performance, which was thought to be humanly impossible until relatively recently.

Pulling off a “Lightning 4-2” requires a pixel-perfect execution of the level’s famous “wrong wrap”—where going in a pipe takes the player to a warp zone that would usually require a slow climb up a vine. Pulling this off quickly requires “bumping” Mario against various walls and barriers mid-jump, slightly altering his position on the screen and enabling the precise positioning needed to activate the glitch.

For years, the TAS of the level was just a few frames ahead of methods that were considered human-viable in a “real-time attack” (RTA) speedrun. But that small difference was enough for the TAS to save an entire “frame rule” over the best RTA times on the level, leaving humans a full 21 frames (about 0.35 seconds) behind mechanical perfection on the level thanks to the vagaries of the game’s loading times.

Back in 2018, runner HappyLee used emulation tools to lay out a new, theoretically human-viable “Lightning 4-2” strategy that matched the TAS’ time down to the frame. But in early 2021, Niftski used a slightly different method—integrating a pair of backwards jumps over piranha plants into a wall jump off the edge of the crucial “wrong warp” pipe—to become the first human to match the TAS time of 25.34 seconds in an RTA of the level.

Just because Lightning 4-2 was technically possible for a human didn’t mean the extremely precise sequence of inputs was reliable enough to start integrating into full game speedruns, though. But that changed recently as runner KingOfJohnnyBoy helped develop a more consistent Lightning 4-2 method that involves bumping off of a question-mark block, rather than a moving platform, to quickly set up the crucial wrong warp” positioning.

With that new method in place, “this framerule that was once thought to be impossible has now been implemented in runs,” as Niftski put it in on YouTube. But to get the new world record, Niftski would have to pull off the extremely tricky Lightning 4-2 in a run that also included multiple “fast acceleration” starts and punishingly precise glitches to skip the flagpole animation at the end of each level (including an exceptionally hard one in 8-2 that requires bouncing off a precisely placed Bullet Bill).

The push for perfection

The full video of Niftski stringing all that together includes a lot of extremely loud exclamations, especially after he realizes he’s pulled off his second “Lightning 4-2” in a row during a run that has been otherwise perfect. His heart rate, as displayed on screen during the livestream, starts increasing before topping out at 188 bpm by the end of 8-4 (“I am completely healthy and do not have any heart condition!” he assures viewers in the YouTube description). When the run is complete, Niftski pops off into a tearful, repeated exclamation of “Oh my god!” and tells himself to “Get oxygen, dude” as he realizes the enormity of what he’s done.

With seven “perfect” levels strung together in a single run, Niftski’s last remaining hurdle is to put it all together with an 8-4 that is just 22 frames faster to match the TAS. That would set a record that would be literally unbeatable, even by a machine, until and unless some currently unknown strategies were discovered to save even more time.

“As much as I’ve stressed how amazing this run is to me, this is not my end goal, and I will not be stopping here!” Niftski writes on YouTube. “I plan to take this category as low as possible.”