UPDATE: After Kosmic’s speed-run was reviewed further, it was discovered that his time was actually off by exactly one frame. His actual speed-run was 4:57.244, the same as Darbian’s, with whom Kosmic now shares the world record. In a follow-up, Kosmic explained where the original recorded time was incorrect:
Basically we know the exact time of the run by the pattern bowser does. His patterns change every frame from power on, so the pattern he gave me is the pattern for 4:57.227.
But, I got a frame of lag when I did [the] bullet bill glitch in 8-2, and lag isn’t like an official frame that the game keeps track of, so Bowser’s pattern isn’t affected by this.
8-4 was 1 frame faster but 8-2 was 1 frame slower so it’s an exact tie.
— Kosmic (@Kosmicd12) October 2, 2016
Kosmic explained that he discovered the lost frame during glitch after uploading the footage and reviewing it further, comparing it to a number of other speed-runs.
After fellow speed-runner Sockfolder investigated the issue to find the precise cause, Kosmic updated the results to reflect the actual time he beat the game in. The problem is apparently related to buffer overflow, something that doesn’t always result from the bullet bill glitch.
Original story follows:
One of the two closest finishes in the NASCAR Sprint Cup Series came in 2003 when Ricky Craven edged out Kurt Busch by 0.002 seconds. The second was nearly a decade later when Jimmie Johnson beat Clint Bowyer by the same. To say that either racer won by a hair would be an understatement.
I beat the world record for the fastest speedrun of Super Mario Bros.! I beat the game in 4:57.227!https://t.co/DKEVRTUuIR
— Kosmic (@Kosmicd12) September 30, 2016
The previous record was held by Darbian, whose time for completing the game stood at 4:57.244. Kosmic's time was 4:57.227, a difference of .017, seconds, or one sixtieth of a second. In other words: a single frame.
Kosmic posted an FAQ under the video explaining his run, answering a number of questions including how he was able to run through Bowser's hammers:
Sometimes you simply jump through a gap in the hammers, and sometimes you actually go right through a hammer. This is because the game can't always handle having all those hammers on screen at once, so some of them don't have hitboxes.
He accomplished the run on an actual NES using the console's original controller. It took the former record holder, Darbian, an incredible amount of time to perfect his previous run, which is why he decided to "retire" at the time, saying "My quest is over!"
Speed-running Super Mario Bros. has become such a popular project that the tricks to improving times are well established. The practice is so well established that each new record has shaved less and less time off of its predecessor. The gains have become so incremental that they're now invisible to the human eye.
One big innovation in the world of Super Mario Bros. speed-runs are a number of flagpole glitches. At the end of each level, Mario has to jump onto a flagpole, at which point an animation bringing him down to the ground and advancing to the next level begins.
The glitch, allowing Mario to pass through the pole more quickly, requires landing at a precise pixel without holding certain buttons and is incredibly difficult to pull-off. Perfecting this manoeuvre is likely one way that future speed-runs will get even faster.
Kosmic concluded by paying tribute to the community that made his new record possible:
Special thanks to Andrewg1990 for paving the way in this game, darbian for pushing the game even more and being very supportive, Sockfolder for finding the setup for flagpole glitch, everyone else who has contributed, and everyone who watches my stream/videos and helps support me.
You can watch his speed-run in its (short) entirety below.