Labyrinth 3 Drop Down Level Wrap Technical Notes
TL;DR included below, as always.
NOTE - All percentages are rounded off to 4 significant figures.
This guide is going to go into detail on the numbers behind the level wrap seen in Tee-N-Tee's 0:32 strat (not the dropdown itself, you will normally need to jump a frame before usual), and assuming the alignment is correct [x position - 07D5, debug will show it]). This guide will also cover the specifics for getting an alignment skip for a faster wrap, useful for ILs specifically.
==BREAKING THE WALL==
When you land, there are two ways you can break though the water slide: A 1 frame right followed by a 1 frame jump, or a 2 frame right along with a 1 frame jump on the second right frame, either way you will need a 1 frame jump:-
[Right,Jump] OR [Right,Right+Jump]
This isn't enough to break through the water slide alone though, as you will need the correct x and y subpixels to clip through it properly. The subpixels fall into the following ranges:-
x subpixels 0-64 y subpixels 0-175
Therefore, you have an x subpixel percentage of 25.39% and a y subpixel percentage of 68.75%, for a combined percentage of 17.46% to break the wall with the correct inputs. If you aren't concerned about the alignment skip, the next step will be to jump against the left wall's collision and then press right for 8-18 frames for a level wrap. 7 does work, although in my first test it didn't.
==ALIGNMENT SKIP==
Next up, the y subpixels need to be split into two parts because they give two wildly different results. So from here on out, I will refer the lower range as -y and the higher range as +y, as follows:
-y = 0-63 +y = 64-175
Once you have broken the slide but before landing, you will have a total of 7 possible frames that you will need to begin holding right on, and the range depends on what x subpixels you have, alongside which division of y you have. -y only uses the first two frames, while +y uses the last 5. These 7 frames are going to be represented as +0 (the first frame) up to +6 (the last frame). Here are some links to the individual frames (NOTE - If you are pause buffering, you will want to pause the frame before the frame you want!):
+0 - https://imgur.com/a/Sw8UB6v +1 - https://imgur.com/a/fqEgGDW +2 - https://imgur.com/a/bTDWT3m +3 - https://imgur.com/a/GoEPWhe +4 - https://imgur.com/a/5k1eRpk +5 - https://imgur.com/a/ubEbE5U +6 - https://imgur.com/a/tHr7FmR
Since there are two radically different results based on your y division and your x subpixel ranges, I have made a table to show which frame the input is needed on depending on your subpixels:
Division | X Subpixels | Frame -y | 0-29 | +0 -y | 30-64 | +1
+y | 0-12 | +2 +y | 3-24 | +2 or +3 +y | 25-36 | +3 +y | 37-48 | +3 or +4 +y | 49-60 | +3, +4 or +5 +y | 61-64 | +4, +5 or +6
In a regular run however, you won't know what your subpixels are, so we need to calculate the percentage of each individual frame to give the odds of the alignment skip. First, we will calculate the percentage odds of getting a division with the correct odds to begin with:
-y = (64/256) x (65/256) = 6.348% +y = (112/256) x (65/256) = 11.11%
(NOTE - The ranges are added by 1 to account for 0 as a subpixel, so it is 65/256 rather than 64/255.)
With these percentages, we can take the percentage chance of the frames leading to an alignment skip and multiply to give the true odds of each frame giving you the skip provided the inputs to skip the water slide are correct:
Chance of frames % | Chance w/ right subpixels %
+0 46.15% | 2.930%
+1 53.85% | 3.418%
+2 38.46% | 4.273% +3 73.85% | 8.205% +4 43.08% | 4.786% +5 24.62% | 2.735% +6 6.154% | 0.6387%
Statistically, we can conclude that the most likely frame for the alignment skip to happen is +3, so if you are pause buffering, you should aim for that frame, as you are most likely to get a skip with it. For pauseless however, this isn't as easy so we will go another way. In the first table, you will notice that with the more common +y division, compared to the -y division, you can actually get frame window of 2 and 3 frames long, particularly towards the end, you can press right in any of those frames that fall in the window. You will want to aim for those later windows instead, as those windows cover 57.81% of those x subpixels and they include the common +3 frame twice (although a solitary +3 frame precedes it), the common +4 frame thrice and the less common +5 frame twice; It's highly unlikely that you will use the +6 frame, it is by far the least common. With this in mind, it is probably for the best to outright ignore frames +0 and +1 completely and chance it on the +3, +4 and +5 frame windows. After that, an 8-18 frame right press after breaking the collision will net you the level wrap.
===============================================
TL;DR:
- To clip the waterslide, you need to press right for 1 frame then jump for 1 frame, or press right for 2 frames and jump for 1 frame on that second right frame.
- You have about a 1/6 chance of clipping the water slide.
- Get a jump against the left wall before zipping if you aren't skipping the alignment.
- Hold left for 8-18 frames to level wrap, if you don't, you end up in an out of bounds area which is essentially a softlock. --ALIGNMENT SKIP TL;DR:--
- If you are pause buffering, frame +3 is the frame you want to start holding right. The frames are linked above, don't forget these are the frames you input on, pause the frame before!
- If you are doing it pauseless, it would be more economical to wait a frame or so to take full advantage of the frame windows.
Results of Community Vote:
For RTA-TB: 24 (96%)
For IGT: 1 (4%)
The result is not close and is why this vote needed to happen.
The default timing method for Sonic 1 1991 moving forward is RTA-TB. IGT is still relevant as a secondary timing method.
-Sonic 1 Mod Team