Topic: Rating system
gnarfk
Joined: 2015-01-05, 15:18
Posts: 70  Likes to be here Location: France |
Posted at: 2019-11-23, 22:32
As a chess player, i think the glicko system (which is an improvement of the ELO system) is good. I think the rating should be calculated after each game, with possible exception of tournaments (the rating evolution should be computed at the end of the tournament). If calculated after each game with only the ratings of the players of the game, it is NOT cpu intensive. I played on lichess, and if i do not play for a long time, when i come back the deviation is bigger than when i left. But, if you take a look at how the FIDE rating works, there are a few values for the deviation (called "coefficient"): 40 for young players 20 for experimented players 10 for masters. Once a player get a smaller "coeff", he can not get back a bigger one. Having only a few possible values for the deviation can make a lot of things easier. (for instance : 200 for the 5 first games, 100 for the next, and 50 if people play more than 10 games in a month ...) if rating is computed after each game, it is possible to include team games in this rating. (variation has to take account of the average rating of each team, and the square of the "team deviation" should be the average of the squares of the individual deviations) Maybe team play should lead to 2 different ratings : individual rating for each players, and a rating for the team. Another thing : in chess, some players think that White pieces have a slight advantage, estimated 50 ELO. It is not taken into account because players play half of the games with white or black. In widelands, some players prefer a color... Maybe, in some maps, a starting position could have a little advantage over the other ones... a record of the maps played, with starting positions and player ratings, should be kept somewhere, just to check the balance of the maps. Edited: 2019-11-23, 22:49
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trimard
Topic Opener
Joined: 2009-03-05, 21:40
Posts: 230  Widelands-Forum-Junkie Location: Paris |
Posted at: 2019-11-24, 22:09
Current updateI'm working on implementing the user game submission now @gnarfk About the ELOYes you're right we could do some simplification, but now that glicko is implemented why go backward? :P.
Well if you want to do pure glicko, you just cannot take into account only the last game. That's the problem. Unless you have some experience with glicko and have an idea for improvment of the current system? I think we will do a sort of mix of both.
Yeap that's definitely something we ought to do. And hoppefuly by simplifying how people submit game it will be easier to implement multiplayer
Yes exactly, see Einstein's paper in the first page of this thread, if you want more detail on how he wanted to implement this apsect!
Yes like starcraft ? Edited: 2019-11-24, 22:11
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gnarfk
Joined: 2015-01-05, 15:18
Posts: 70 Likes to be here Location: France |
Posted at: 2019-11-25, 06:59
Let me explain the FIDE rating system. There is the coefficient (which is our "deviation"). When a player meets another, there is an "expected result" calculated from the two ratings. (for instance, player A is 2000 with C_A = 40, player B is 2196 with C_B=20 , A is expected to do 0.25, and B is expected to do 0.75). The variation for A is the A coefficient multiplicated by the difference between the effective result and the expected result. (If the result of the game is a draw, the effective result is 0.5. The variation for A is Coeff_A x (0.5 - 0.25)= +10 , the variation for B is Coeff x (0.5 - 0.75) = -5 ) One problem of the FIDE system is that it does not take the opponents coeff into account, but that could be fixed ... For instance : coeff_A = 50 * Deviation_A / Deviation_B (where 50 is arbitrary chosen, and can be modified ...) Edited: 2019-11-25, 07:08
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trimard
Topic Opener
Joined: 2009-03-05, 21:40
Posts: 230 Widelands-Forum-Junkie Location: Paris |
Posted at: 2019-12-08, 16:01
FIDE system seems nice, but I do think glicko is superior in long term. Though, it seems pretty easy to implement so maybe we could try adding it too at some point? Afterall the code is organized from the start to have many different rating system to compare them Stage 0 - completed!Ok, user submission of game is now working as intended in my test. I think it's finally time to test on the alpha website? That way, it would be easier to calculate the current score of the players, as everyone could add games :). kaputtnik ? Or someone else? What does work
Nb: to add games, users playing in the game need to be added first by the admin, in the alpha. What need to be worked on soon
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gnarfk
Joined: 2015-01-05, 15:18
Posts: 70 Likes to be here Location: France |
Posted at: 2019-12-10, 07:01
glicko is superior to fide system if you want every game in the same period to have the same value. FIDE-like modified system as i said is superior if you want easy calculation , game by game calculation . in this case, the last games have more importance in the rating. ( exponentially decreasing , by a factor depending on the deviation ) At some point, if you use glicko system with calculation by period, you should think about a minimal number of games to play in order to have the rating replaced by the new one. For instance in French Chess Federation (FFE) rating (which tends to be replaced by FIDE rating), if a player plays more than 9 games, the rating is fully replaced. Else, it is an average between old rating and new one. It is a point that makes me prefer FIDE system. It has a "memory" for old games, which progressively vanishes with new games played, not brutally at the end of a period. Edited: 2019-12-10, 08:45
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trimard
Topic Opener
Joined: 2009-03-05, 21:40
Posts: 230 Widelands-Forum-Junkie Location: Paris |
Posted at: 2019-12-10, 22:35
I'm sold, we'll have to test that too! I'm basing myself on glicko and simple ratio for now. But I'll add elo and fide just to see what the difference would be. At that point, we could decide which seem the most appropraite. And as I said, maybe we'll mix some of them. Anyway, got some new pages made, and though this one might interest you people
and yes, those are test data don't worry Edited: 2019-12-12, 10:04
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gnarfk
Joined: 2015-01-05, 15:18
Posts: 70 Likes to be here Location: France |
Posted at: 2019-12-11, 18:01
i have been thinking about FFA games. i can think of a way to do that (at least with FIDE system, but it can be adapted to glicko) for instance : players : A,B,C and D. If player A is the only one winning. Then, A wins against everybody, and the other ones draw each other. The full game will count as it were : A wins against B ; A wins against C ; A wins against D ; B draws C ; B draws D ; C draws D. But each game has to count only to a third of a game (with FIDE, we divide the "coeff" by 3) This system is also good if there are several winners (in autocrat if 2 players survive but can't finish each other, they draw each other, they win against every other, and the other players draw each other)
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WorldSavior
Joined: 2016-10-15, 03:10
Posts: 2094 OS: Linux Version: Recent tournament version  One Elder of Players Location: Germany |
Posted at: 2019-12-11, 19:22
That's interesting. Suggestions: Include draws and maybe amazons
I'm not sure if this model can be so useful for a ffa-match. After all ffa can be about a lot of luck... Wanted to save the world, then I got widetracked
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gnarfk
Joined: 2015-01-05, 15:18
Posts: 70 Likes to be here Location: France |
Posted at: 2019-12-11, 19:40
Yes it is. It probably should be an independent rating. But if it is possible, why not ? No one forces you to play ranked FFA games. (as i said, players should decide before the game if it is ranked or not) But some people might want to play this type of games.
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einstein13
Joined: 2013-07-28, 23:01
Posts: 1118 One Elder of Players Location: Poland |
Posted at: 2019-12-12, 08:56
I know that this is one of the possibilities to solve the free for all games, but we already have a mathematical solution for that. Of course we can adopt multiple rating systems with multiple types of calculations, but it has to be created smart, because we don't have many coders Unfortunately server that the paper were uploaded is out of order. So anyone who wants to read what is inside, please send me a direct message with an email and I will send this paper there. einstein13
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