Im sure someone has found this out in the past but anyways i found a 1 frame faster fpg over normal, i guess if your one frame short in underground you can use it
ah, i figured someone has found it before, i just thought the extra frame came from running speed or something
It's because the game gives you more acceleration when you have "running speed". But this "running speed" isn't directly related to your current speed, but rather it comes from running on the ground with 28 or more speed. When you do the usual Sockfolder FPG setup, you jump off of the stairs with 26 speed, so you never get this "running speed" before you touch the flagpole. But if you land on top of the stairs and then run for a frame, you'll get the "running speed" and that makes you accelerate slightly faster when dismounting the flagpole, saving a couple of frames.
Incidentally, I also noticed this phenomenon back in 2019: But I was told back then that it was already known to TASers well before that.
Following investigations regarding the accuracy and integrity of FCEUX, the SMB1/2J moderation team has decided that FCEUX will not be permitted for future submissions, effective September 17th, 2023. The accuracy of FCEUX has come into question following 108Pi's discovery that the current SMB1 Warp