Chusan: add a patch that removes recent scores from rating calculation

[nyairobi]

This patch effectively removes R10.

Motivation

The in-game rating in Chunithm is calculated roughly as follows (in pseudocode):

let r = 0
for s in best_scores.take(30):
    r += s
for s in recent_30_scores.sort().take(10):
    r += s
r /= 40

The general consensus is that taking recent scores into account defeats the purpose of the overall rating as a skill/progress tracker; they can deflate it from 16.x to 14.x when you're all-playing easier charts, or they can artificially inflate it when you spam your best chart a dozen times. Some people choose to hide the in-game rating specifically for this reason.

The patch

0x6FF272 is the number of recent scores taken (10->0) 0x6FF285 is the divisor (40->30)

The resulting value matches with a third-party score tracker that specifically only uses Best30.

Disclaimers

• "... or they can artificially inflate it when you spam your best chart", so yes, the ceiling becomes lower which can matter if you're pushing for a landmark rating (16.0/16.5/17.0).
• This is a client-side change (and it works immediately after login), but the server does see it after a finished credit. This probably doesn't matter but I'd still rather mention it.'
• I haven't tested whether it's reversible, but I don't see why it shouldn't. I'm not actually altering the recents queue, only the procedure that calculates the overall rating.
• I made this and I'm ok with it being public.
  • At the same time I understand if it doesn't get merged, since it's a behavioral patch rather than a technical one.

[mon]

I mean look, some of my earliest hex edits were changing SDVX III's score algo from the default to "percentage score" and "maximum possible score from here", so i totally get you. This seems to change the rating algo to something objectively more accurate (which subjectively might be worse or better). An easy merge.