What K factor should be used if two players are in different K factor brackets?

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tomitank
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What K factor should be used if two players are in different K factor brackets?

Post by tomitank » Sat Jan 09, 2021 10:49 am

https://chess.stackexchange.com/questio ... r-brackets

Is the accepted answer really correct?
So is there a case where the points are not transferred one in one?

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Ajedrecista
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Re: What K factor should be used if two players are in different K factor brackets?

Post by Ajedrecista » Sat Jan 09, 2021 12:16 pm

Hello:

I do not know the answer, but I can tell what FIDE (not USCF) did in August 2015. Do you remember the case of John Burke, who achieved a FIDE rating over 2600 Elo being 13 or 14 years old? I searched the rating changes of him and other player with different K. I got Burke (2258 Elo at that time and K = 40) vs Bachmann (2626 Elo at that time and K = 10). I do not know who played each side of the board. Bachmann won and got +1 with K = 10, while Burke got -4 with K = 40 at the 3rd Annual DC International:

Burke, John M USA (August 2015 calculations)

Bachmann, Axel PAR (August 2015 calculations)

There should be more examples involving Burke in August and September, 2015. FIDE policy was doing calculations with different K's.

Regards from Spain.

Ajedrecista.

Sesse
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Re: What K factor should be used if two players are in different K factor brackets?

Post by Sesse » Sat Jan 09, 2021 12:23 pm

tomitank wrote:
Sat Jan 09, 2021 10:49 am
Is the accepted answer really correct?
So is there a case where the points are not transferred one in one?
The Elo system is a statistical system. You don't “win” or “transfer” points; the statistical estimate of your playing strength merely becomes more accurate in the light of new information. (This is also why you don't get e.g. more points for winning important games.) Often, the math comes out to one player winning N and the other losing N, but indeed, not always.

tomitank
Posts: 235
Joined: Sat Mar 04, 2017 11:24 am
Location: Hungary

Re: What K factor should be used if two players are in different K factor brackets?

Post by tomitank » Sat Jan 09, 2021 1:22 pm

Thanks guys!
I was unsure, but thank you for the confirmation!

-Tamás

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