April 7, 2021 may have been a historic day in the world of speedruns. Speedrunner Niftski managed to complete Super Mario Bros in 4: 54: 948. This time is not just the new world record of the most famous video game ever, it is also the last barrier. The first three digits of this record may never change again.

A short game

The importance of this record is related to two factors. The first is that Super Mario Bros. is a very short game, if you know how to complete it. Playing only eight of the thirty-two levels that make it up (1-1, 1-2, 4-1, 4-2, and the entire eighth world) you can save the princess.

This makes speedruns very difficult to improve. The levels are short and the possibilities of shortening the path are already very few in themselves. Since glitched runs were allowed, it went from a record of 5:07 to the current 4:54, only after a decade of trying.

But there is another variant that makes 4:54 a probably unsurpassable number. It's something that all Super Mario speedrunners get to know and hate from the very first runs: the framerule. 

21 frames

Due to the limitations of the console Super Mario Bros. was developed for, the NES, the game can only update a certain amount of times per second. These updates, among other things, check if a new layer needs to be loaded. 

The game can then load a level once every 21 frames, which at 60 frames per second is 0,35 seconds. This affects speedruns enormously. To give a practical example, it is as if at the end of each level there is a bus that takes Mario to the next level, and that leaves at intervals of 0,35 seconds. This interval is called framerule.

This entails that no improvement in a run is significant, unless it saves a third of a second in a single level (excluding 8-4, the last level that ends the instant Mario defeats Bowser). It seems like a very short amount of time, but in a fast-paced game like Super Mario Bros. it's an infinity.

Almost perfect

The speedruns of Super Mario Bros. have arrived at an optimization that borders on perfection. Every glitch was exploited, even those that for years were deemed humanly impossible to perform.

From Fast 4-2, which requires a manipulation of Mario's position amounting to fractions of frames, to the bullet glitch of 8-2, in which the player has to wait, apparently losing time, for the bullet to position itself perfectly, until reaching the Flag Pole glitch.

It is to this last glitch that some appeal to still believe that 4:53 is possible. Even back in the days when the first speedrunners dropped below the 4:56 mark, many believed it would not be possible to go further.

This is because the latest glitch shown by the TAS (tool-assisted speedruns, where the game is run from a computer with perfect inputs), the Flag Pole in fact, was considered humanly impossible. This theory was disproved when the first speedrunners managed to perform the glitch with some consistency.

But this time it's different. Even the TAS can't go below 4:54. Perfection, after years of research on the game code, in a game run from a computer, is 4: 54: 032. Almost a second below the best human performance, but nonetheless at a 4:53 framerule. 

Even though Super Mario has reached its limit, the fact remains that over 35 years old since release, this game still manages to animate a huge community. The speedrun video has over 300.000 views, and another video, which tells the story and the execution of this match, over a million. I don't think there is better proof of the quality of the title than this one.