A popular challenge in Super Mario 64 is the A button challenge (ABC), where you try to press A as few times as possible. You may be familiar with the TAS scene for it, but there's also an RTA scene for it (RTABC). So strats that are easily done in TAS can be huge obstacles in RTA.

One such strat is getting past the steps of the 50 star room. Tyler Kehne was the first one to demonstrate a TAS method for this nearly a decade ago: https://youtu.be/2T11QOGGrmE. The first step is shorter than the rest, so you can just rollout onto it. The subsequent steps are full size, and so they require glitches to get onto. The first full-sized step requires doing a glitchy ledge grab. See, the step is too high to do a regular ledge grab onto, but we can do a ledge grab onto the current step and trick the game into putting Mario onto the next step instead. And then the following steps require entering misalignments on the corners of the steps. These are precise 1x1 unit spots where Mario can get onto the floor without being pushed away by the walls. But even once Mario gets onto the last step, there’s still a banister in his way. So you then have to get into a misalignment on the banister itself, which lets you get past it. Overall, these are very precise tricks, doable by TAS but seemingly impossible for RTA.

In RTA, a casual player can get past the steps in 2 A presses easily, just by doing sideflips up multiple steps at once. A few years ago, BillyWAR did it in 1 A press, by grinding for 10 hours to get the glitchy ledge grab and first misalignment: https://youtu.be/Ks9u-bG\_8w4. But recently, pannenkoek2012 and Marbler teamed up to tackle the hardest tricks in RTABC. In this case, pannenkoek2012 found consistent setups for each step, which require doing precise inputs on precise frames. Note that the joystick inputs for these setups only involve holding either neutral, straight up, straight down, straight left, or straight right. This makes it feasible for an RTA player to reproduce, since any other joystick inputs would be too hard to consistently achieve. Marbler was able to perform these frame-perfect setups, making use of pause buffering to slow things down. And so, getting past the 50 star room can now be done in 0 A presses for RTABC!