Talk:Elo rating system/@comment-77.54.95.168-20120120133219/@comment-3014924-20120124110251

I've read the math parts of ELO system before answering (I'm statistician btw). Technically, you could. The function is based on the difference of ELO value of both opponents that elaborates the Win probability: D=difference of ELO win chances = 1 / (1+10^(-D/400))

400 is just a number introduced to have a wider range.

How to explain? Let's say Team A is twice as strong as team B. Team A has 66% chances to win (note that: to be 2 times stronger is to have 66% win chances!). Actually the ELO difference between the 2 would be 120 ELO. That's because they introduces that 400 factor. If they wouldn't have, the difference would be 0,3. But it would somehow suck to say: "Hi, I'm ELO 0,85 and you 0,55. I'm so strong).

Anyway, let's move on. As the formula works on D (difference of ELO), you could start at 0.

But RIOT just followed how the results of the chess federation history.

When they started to use ELO, they decided that International masters would be ELO 2500. This induced progressively the level of other players:

-2500: International Master -2000: national level -1600: Very good player -1200: Beginner -1000: Child level/Total beginning level.

That's why, when joining chess, you'll start 1200.

RIOT followed their system. But it flaws it compared to chess.

The top players started 1200. You're no beginner when joining ranked. So in pratice, the long time established scaling from chess doesn't work. And, contrary to chess, starting 1200 doesn't mean at all at starting low. Which makes 1200 a bit messy as you can have anything at that ELO. -