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I'm looking to implement an ELO ranking system. I've read the wikipedia articles and I'm confused about the start rank for players who enter the system at a later point. The common solution is to use a provisional ranking system but I'm curious if anyone can point me to specific numeric details:

what K value do new players get? how long does a player stay in provisional mode? how does K value change as rank changes? I'm sure there are many variations, I'd just like to know actual numbers for a system that someone has implemented successfully.

Thanks for your time.

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What is an "ELO ranking system"? – Henning Makholm Jan 30 '12 at 2:04
@Henning, Arpad Elo invented a system for ranking chess players, based on their records in games against each other. It was adopted by the US Chess Federation, and later by the international organization (FIDE), and it has also been applied in contexts outside of chess. In essence, your rank is the average of your opponents' ranks, adjusted by your record against said opponents. The details are no doubt searchable. – Gerry Myerson Jan 30 '12 at 2:09
up vote 1 down vote accepted

I believe the parameters used by the United States Chess Federation in its implementation are given at this link.

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I believe that's a bit overkill for my purposes. I just want to design a system that gives a roughly fair initial ranking to new comers to the system. My initial thought was to always give new comers an initial rating equal to the system's global average and keep them at a high K level for the first 30 provisional games. Does that makes sense or do you see any problems with that approach? – user257543 Jan 30 '12 at 23:04
You asked for "actual numbers for a system that someone has implemented successfully." The USCF is such a someone, and I think you will find the "actual numbers" at that link. I have not implemented a system, successfully or otherwise, so I don't feel qualified to answer the questions in your comment. The FIDE has also implemented Elo, and some details are at – Gerry Myerson Jan 30 '12 at 23:30

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