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Linearity

Posted By: eXtreme Gammon
Date: Friday, 14 May 2010, at 1:04 a.m.

In Response To: Linearity (eXtreme Gammon)

Note about the Elo system

The formula displayed on XG is the one use by all bg site. It is the same used in chess (Elo on wikipedia):

Basically the formula is Probability to win = 1/(1+10^(delo/factor))

• in chess the factor is 400
• in BG it is 2000/sqrt(N) where N is the match length¹.

So to get the probability of winning than in chess you can play 25 point matches. This is the number people have came up with using PR, which is an indirect way to reach it and tend to proove that the formula I gave for equivalence between PR and Elo (1 PR = 33 Elo) are about right.

¹ I am not sure who came up with that formula, I think someone from FIBS. Checking about 200,000 games on Gammonsite gave very satisfactory results and tend to validate that hypothesis.

Messages In This Thread

• Elo difference mapping to Snowie ER
  Klaus Evers -- Sunday, 9 May 2010, at 10:03 p.m.
  • Elo difference mapping to Snowie ER
    Leonardo Jerkovic -- Sunday, 9 May 2010, at 10:16 p.m.
    • Elo difference mapping to Snowie ER
      Christian Plenz -- Monday, 10 May 2010, at 2:17 a.m.
      • Elo difference mapping to Snowie ER
        Rich Munitz -- Monday, 10 May 2010, at 2:34 a.m.
        • Elo difference mapping to Snowie ER
          Iancho Hristov -- Monday, 10 May 2010, at 4:57 a.m.
        • Elo difference mapping to Snowie ER
          Neil Robins -- Monday, 10 May 2010, at 5:36 a.m.
          • Elo difference mapping to Snowie ER
            Timothy Chow -- Monday, 10 May 2010, at 3:38 p.m.
            • Elo difference mapping to Snowie ER
              Rich Munitz -- Monday, 10 May 2010, at 5:33 p.m.
            • Linearity
              Chuck Bower -- Thursday, 13 May 2010, at 7:34 p.m.
              • Linearity
                Timothy Chow -- Thursday, 13 May 2010, at 8:57 p.m.
              • Linearity
                Rich Munitz -- Thursday, 13 May 2010, at 11:46 p.m.
                • Linearity
                  eXtreme Gammon -- Friday, 14 May 2010, at 12:48 a.m.
                  • Linearity
                    eXtreme Gammon -- Friday, 14 May 2010, at 1:04 a.m.
                    • Linearity
                      Tom Keith -- Saturday, 15 May 2010, at 12:11 p.m.
  • Reminder: I was interested in Snowie Error Rate difference
    Klaus Evers -- Monday, 10 May 2010, at 7:14 a.m.
    • Reminder: I was interested in Snowie Error Rate difference
      Stick -- Monday, 10 May 2010, at 7:50 a.m.
    • Reminder: I was interested in Snowie Error Rate difference
      Neil Robins -- Monday, 10 May 2010, at 3:32 p.m.
      • Agreed: 100 elo ~ 2.6 Snowie ER
        Klaus Evers -- Monday, 10 May 2010, at 6:24 p.m.