The only ranking shown was A-7. So perhaps it’s an alphabetical and numerical system. Such as
:
X not yet ranked
F class is lowest rank
D is below average
C is around average
B is above average
A is high above average
S super or very tip top
F1=1
F2=2
D1=11
C1=21
B1=31
A1=41
S1=51
S10=60
or perhaps an A-Z and 1-10 system? Of course all speculation but it gives something to think about.
Maybe, once you reach a certain letter it would take a very long time to move down (say from B to C) but you go up and down fairly well within the numbered system (1-10)?
Also, was it just me or did the multiplayer screen look kind of bad? Hopefully it’s a placeholder.