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I'm learning chess and I practice in the chess.com app. I don't understand how the winning points are calculated in every match.

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Most chess sites use some variant of the Elo rating system

If you have a much higher rating than your opponent, the expectation is that you will win. So if you do win, then we haven't gained that much information, so the change in rating for both you and your opponent will be small. If your opponent wins, there will be a much larger change in rating as their win was less expected.

In your case, you have a rating of 775 and your opponent had a rating of 651. Since you have a much higher rating, winning didn't result in a large rating increase. If you had won against someone much higher rated than you, you would have experienced a much larger rating increase.

Mathematically, the rating change of each player is calculated as some empirical constant (K, 32 is often used) multiplied by the difference between the actual score and the expected score of that player against the other. The expected score is calculated from the difference of the two ratings.

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    To add to this, in online chess players often get a "preliminary" rating before they've played many games, where rating gain/loss is amplified significantly until the player's played enough to get an "established" rating so to speak. After they have their established rating, the rating gain/loss from each game is not as dramatic as in the beginning. So if the original poster was wondering why he got more gain from wins in similar situations before, I would guess this would be the explanation.
    – Scounged
    Commented Aug 12, 2019 at 20:14
  • @Scounged: We had some joke going on on a go server where they guy got to the highest possible rating while still preliminary. I suppose the same kind of horror could happen in chess when the guy wins against the top-rated players right off the bat.
    – Joshua
    Commented Aug 12, 2019 at 22:22
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    Chess.com uses the Glicko system, which means there's not just some K constant - the amount your rating changes depends on the Rating Deviation (basically an indicator of how reliable a rating is) of both you and your opponent.
    – D M
    Commented Aug 13, 2019 at 2:54
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    For those wondering, Glicko is like an improved version of Elo. For some values of improved.
    – Mast
    Commented Aug 13, 2019 at 9:43
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    This answer would benefit from a brief explanation of what ELO is modeling. Namely, it is modeling relative skill level, based on the idea that when player A with rating n plays against player B with n - x, player A is expected to win y% of the time, for some x and y. (Original Elo uses x = 100 and y = 64, but other systems might use different values.)
    – Jasper
    Commented Aug 13, 2019 at 14:41

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