Sunyaku wrote:
I disagree that TFW is truly "glicko".
Sunyaku wrote:
I would prefer to see uncertainty removed altogether for anyone who has played 20 games against human players. This would, in effect, make TFW a "glicko" system, as you mentioned.
As far as I know, the rating system used by TFW is an exact implementation of Prof. Glickman's "Glicko" system, which does feature rating uncertainty (for a description of the system, see:
http://www.glicko.net/glicko/glicko.doc/glicko.html ). In chess, they don't have rating uncertainty, because they're using the older "Elo" system.
Sunyaku wrote:
The current rating system is a meaningless indicator of a player's skill because of rating attrition via a perpetually accumulating uncertainty.
I'm not sure why you keep referring to rating uncertainty as "attrition". Uncertainty doesn't lower your rating. A 1500(300) player has exactly the same rating as a 1500(50) player - 1500. He will just appear lower on the boards. If he comes back and plays at the same level he did before taking a break, his rating will remain 1500 (just with a lower uncertainty), and he'll move back up on the boards.
Sunyaku wrote:
Put in "glicko" terms, IMHO the Rating Deviation (RD) accumulates much too fast.
That is certainly an argument that could be made. I don't know how fast it accumulates in TFW, so I can't really argue for or against it.
(Jed, if you're reading this, could you tell us the rate you picked for RD accumulation?)
Sunyaku wrote:
The proposed z(y) wouldn't be any different.
If I understand queeshai correctly, he isn't suggesting changing anything in the actual system, only in the way the results are displayed: display (rating-RD) instead of just (rating).
Sunyaku wrote:
For the most part your post was accurate, but the one thing that is not accounted for is the fact that when an experienced players returns, their REAL rating drops like crazy. For example, once upon a time I was rated over 1700 in both categories. When I came back from hiatus, I had almost max uncertainty. If I WON a game against nearly any player, I would gain very few, if any rating points. BUT, if I LOST a game, I would stand to lose 30-100 rating points a shot. Thus, with a high rating and high uncertainty, it's nearly impossible to drive your uncertainty back down without completely trashing your rating.
High uncertainty makes it easier for your rating to move around, in both directions. When an active player wins (or loses) 3 games in a row, the system just assumes that they're having a good (or bad) day, and only slightly shifts their rating. They would need to have several such days for their score to change appreciably. However, when a returning (or sporadic) player has such a streak, the system assumes that the streak (good or bad) is indicative of their current skill, and adjusts the score accordingly. This is because with such a player, the system doesn't have a lot of other recent data to work with.
As for the specific example you cite, note that a 1700 score is extremely hard to hold on to, regardless of uncertainty. I estimate that when playing against reasonably good players (say, 1300-1400), the 1700 would have to win about 9 out of 10 games just to break even (If I have more time later, I'll try to plug some numbers into the equations and verify this). In other words, they would lose 10 times as many points for losing a game, as they would gain for winning a game.
Now, if the 1700 player has a low uncertainty, they might gain 1 point for winning, and lose 10 points for losing. This would mean that a streak of 3 losses might not be so bad (but they'll still need to win 30 games to make it up).
With very high uncertainty, you might look at 7 points for winning, 70 points for losing - which is commensurable with your report. You still need to win 10 games per loss to maintain your score. It's just that the system punishes you more swiftly for not doing so.
Sunyaku wrote:
Since I've been on break again, my current rating and uncertainty level makes me look like a noob.
I agree that this is a problem. However, I believe the problem lies with the rating assigned to new players. Among established players, 1300 is actually a pretty good score (only achievable by players that have improved their play quite a bit since their noob days). I would say that most beginners play more on par with an 800-900 player.
This means that giving beginners a rating of 1300(350) is unrealistic. It's not very bad, because they have a high uncertainty (so their first losses quickly put their rating in a more realistic range), but it does create some problems:
1. Unrealistic ladder matching for beginners, which is demoralizing for them, and boring for their opponents.
2. The sharp rating drop in the first few games is also demoralizing for the beginner.
3. It makes good but inactive players look bad in comparison (didn't think of that one before reading your post).
4. A beginner that happens to win their first few games (against other beginners), will briefly shoot up into the top 20.
I believe starting beginners with something like a 900(350) score will remedy these problems.