Figure out how to show classic and lazer scores on leaderboards

[peppy]

Some initial discussion has already happened surrounding this, and we did a poll (results here) to gauge overall community feelings. Basically, we need to decide how (and where) to show lazer and stable scores beside each other.

Nothing has been finalised yet, and this issue is not intended to spark new discussion but simply track the task for future attention.

[bdach]

Are we running with the results of the poll here, i.e. unified leaderboards? Don't think this requires any further direction discussion then.

It likely will require implementation discussion and I'm not entirely sure I'm up to speed as to how the background/infra work is looking in that respect.

@peppy Do we have any up-to-date docs on how we're doing with score storage backend-wise? There's https://github.com/ppy/osu-infrastructure/blob/master/score-submission.md, but it looks a bit stale now (last update >1 year ago).

[peppy]

I think the general consensus is "show as many scores as we can on the same leaderboard".

And with the direction that we've been taking scoring (score v2; migration of scores from v1 to v2) this is looking more feasible than ever.

The way I currently see things working are:

• The default leaderboard view in lazer will show all scores (legacy, lazer, all mods)
  • Classic scores (and other special cases) will be clearly marked. Mod multipliers may be applied for classic scores, to account for no slider head accuracy etc. (will need its own issue thread, was touched on in a community meeting and we came to a rough consensus but needs testing)
• The default leaderboard in stable will either show only legacy scores, or will also include lazer scores as well. This needs UX and infra considerations, but in theory should be feasible
  • This relies on stable also switching completely to score v2 to make sense. It can come later down the track (ie. next year) alongside implementing very basic support for "classic scoring" display in stable for those that prefer it.

If this answers all questions from an implementation perspective, and there's no pushback on this direction from users then this issue can be moved out of discussion phase. Hopefully with a tasklist created outlining each of the steps in making the above happen.

[bdach]

This relies on stable also switching completely to score v2 to make sense

What does that mean in the context of pending scoring changes like #24166? Namely, if that change happens, are we porting it back to stable?

alongside implementing very basic support for "classic scoring" display in stable for those that prefer it

I assume we'd use the same method we're already using in lazer, more or less? Means we need to get #23763 out of the way first (that issue is really becoming a blocker, with 2 dependent issues now).

[peppy]

This relies on stable also switching completely to score v2 to make sense

What does that mean in the context of pending scoring changes like #24166? Namely, if that change happens, are we porting it back to stable?

Maybe..

I assume we'd use the same method we're already using in lazer, more or less? Means we need to get #23763 out of the way first (that issue is really becoming a blocker, with 2 dependent issues now).

Correct.

But this is all under the assumption that we can do this without losing our sanity. Probably fine**.

[bdach]

Maybe..

I understand the tentativeness on this one but it really needed asking. Ignoring stable is an option but you will likely see people complain that lazer and stable scores share leaderboards despite in actuality not sharing scoring systems.

I guess, to avoid touching stable, we could consider trying to disable new scoring changes with classic mod active? But I kinda wanna barf even thinking about what that would entail. So maybe best to just not think about it too much..

[peppy]

If the goal is to share leaderboards, there are going to need to be changes made to stable. Once we decide on what needs to change, making it happen should not be too hard. Just have to make sure we finalise things first so we don't end up with migration on migration on migration.