Screen resolution is exploitable in taiko

[buyaspacecube]

Playing on a wider resolution can give big advantages in taiko for a number of reasons, the main being the incorrect scroll speed calculation when playing with hardrock. An in-depth explanation can be found under "Calculation" and "Analysis" at https://osu.ppy.sh/community/forums/topics/1851087?n=1 but to summarise, whichever line calculates the scroll speed increase with hardrock fails to account for the HUD and means notes are visible for longer on wider resolutions. This is most noticeable when playing HDHR without scorev2, as seemingly the point where notes fade out scales incorrectly too making wider resolutions far easier

Due to the benefit of this extending past resolutions like 16:9, players often externally modify the game to stretch their resolution past the ones provided in-game to gain what is definitely an unfair advantage. This is also often combined with skins using extra large circles to almost nullify the effect of hardrock altogether, compare this clip of HDHR on a normal skin and resolution to this one using the above exploits on the same map

Less damaging but still worth mentioning is notes with nomod cutting off only at a resolution of 8:3, a resolution again only accessible by external means

This is definitely a tricky thing to "fix" as outright fixing the calculation or cutting off notes earlier would unfortunately lower the current skill ceiling of high velocity reading. From my perspective the ideal solution would be something similar to how gamma is treated in cutting edge, still allowing the settings but not submitting plays using them for ranked

I bring this up now due to ppy/osu#37168, an upcoming pp change that will sadly make the benefit of exploiting reading mods even greater

[overdahedge2014]

Here's a demonstration I put together of the same map on HR, with the same skin, once on a significantly ultrawide aspect ratio and once on standard 4:3. I frame-advanced the video to check how long the first note was on screen with each of the two, and found results of 39 frames on ultrawide compared to 34 on standard. This is essentially the same effect as lowering the AR of all maps by changing settings in obscure and unintuitive ways, and at the top level of high-scroll difficulty where every extra frame of notes on screen is a big deal, this becomes an extreme advantage

This video may make ultrawide actually look harder to read due to how much smaller each note is on the scale of the entire screen, but that's where 'big note skins' which have purposely larger taiko-note objects come in to nullify this drawback

[tsunyoku]

For my understanding, please confirm:

• this requires using resolutions with aspect ratios that monitors would not natively choose to use
• the advantage comes from a wider playfield allowing you to see more notes

Are the resolutions being used selectable via the in-game UI or are people manually editing configs to achieve this? How long has this been a thing? Is top end play relying on such abuse?

[buyaspacecube]

• the advantage is not exclusive to non-native resolutions, as the wider the better no matter what. however since the advantage has no limit players have no reason to stick to the confines of native resolutions
• yes the advantage comes from seeing more notes, as simple as that for nomod and with a bit more nuance for hardrock. there is a calculation in place to try and prevent this with hardrock and keep the same amount of notes on screen, but its doing it wrong (detailed in https://osu.ppy.sh/community/forums/topics/1851087?n=1)
• an small advantage is still gained from using one of the wider resolutions available in-game resolution (wider is always better so 16:9 beats 4:3) but this is small enough that some hardrock players still choose 4:3 for preference. the resolutions used to make this truly unfair are only accessible by editing the config or externally changing resolution otherwise
• this has been known for at least a few years and only caught on more over time, i'm a little upset myself or anyone else didn't make this issue sooner but the next best time to do something is now
• this has definitely assisted top end play over time, the nomod/dt capping at 8:3 bit in more recent reworks where mechanics are favoured and definitely the hardrock side if the pp change linked above goes through. i wouldn't say top end entirely relies on it though, with some top reading players frowning upon it and choosing not to use it