 |
|  |
 |
|
Gavrushka
|
 |
Darlington,Co. Durham,UK
Apr 2001 time: 05:18
|
|
Well I never..... There is one floor in this entire debate.... The rankings are no longer being updated.. ... So the argument is kind of academic... It is over three months since the results were last calculated...
Keygen the Formula for the new system is at the start of every new rating thread...Calling it new is a misrepresentaion however, it started with Gameleague, apart from the stake was reduced from 20% of your points to 10%, to take into account that in PBEM there are more results per game.
I actually do not think it matters all that much which system is used... I only started using the Gameleague system because I was too thick to understand the other system . BUT I do prefer it because it is easier, and seems to represent ability better...
I think the biggest issue is the players that only want to be rated in games they will score positive at... this kind of defeats the object of having a ratings system... I appreciate the Blackice comments about bad land... But any game creator with 30 minutes of effort can equalise the land, and make the game more enjoyable, fairer, and longer lasting... when games can run for years the 30 minutes should be a worthy investment... SO maybe rules for game creation should be applied too.
But to reiterate, this is just all gibberish unless someone takes the mantle of updating the rankings onboard , and I would strongly suggest you forget about holding a vote as to what system to use, and instead let someone take over the ratings, and use whatever system they see fit.
Oh and by the way, hello everyone! 
|
|
|  |
 |
|  |
 |
|  |
 |
|
quinns
|
|
quote: Originally posted by blackice
So show some people some examples Quinn show them side by side the difference. Show us all why your system for chess is better. Use some examples of current random players. It is your system explain to us all by side by side examples of why your system is better.
That is only fair for an informed vote. Besides you solver and me are probably the only ones who could figure out your system. The new is quite easy and self explanitory ( user friendly ). On that note I think people should fully understand what your system is explain it to us in full detail with examples please. |
Okay.
Here is the example:
Albert rated 20.
Bob rated 15.
Charlie rated 15.
Dallas rated 15.
GameLeague Based Ratings Calculation:
Power Graph order at turn 9 = Albert, Bob, Charlie, Dallas.
Wagers:
Albert = 10% of 20 = 2 points
Bob = 10% of 15 = 1.5 points
Charlie = 10% of 15 = 1.5 points
Dallas = 10% of 15 = 1.5 points
Total Wagered = 6.5 points.
Percent Distribution = 46%, 29%, 17%, 8%
Wagered Points Distribution = 3.0, 1.9, 1.1, 0.5
After Turn 9 ratings:
Albert = 18 + 3.0 = 21.0 (net change + 1.0 rating points)
Bob = 13.5 + 1.9 = 15.4
Charlie = 13.5 + 1.1 = 14.6
Dallas = 13.5 + 0.5 = 14.0
Albert is playing in four other games exactly similar to the one above, where he plays against 3 much weaker players than himself. So that now, after the first 9 turns of all of his games,
Albert has a new rating = 25 (GameLeague Based)
(20 + 1.0 + 1.0 + 1.0 + 1.0 + 1.0 = 25)
--------------------------------------------------------
Differential Based Ratings Calculation:
Power Graph order at turn 9 = Albert, Bob, Charlie, Dallas.
Albert (20) defeats Bob (15) -- Ratings Points Differential = 20 - 15 = 5
Probability of Lower Player Winning = 1/[2 + Differential**2] (Note: **2 means squared)
Probability = 1/[2 + (5)**2] = 1/27 = 0.04
Because Albert is higher rated than Bob,
Change = 0.04 / 2 = 0.02 points.
[Note: If Bob had defeated Albert then the change would have been (1- 0.04) / 2 = 0.48]
So that Albert gains 0.02 points and Bob loses 0.02 points.
The calculations are the same for Albert defeating Charlie and Dallas. So Albert gains 0.02 points for defeating Charlie and 0.02 points for defeating Dallas.
The total calculations done are: Albert defeats (d.) Bob, Abert d. Charlie, Albert d. Dallas, Bob d. Charlie, Bob d. Dallas, Charlie d. Dallas. We are highlighting on Albert so I will just focus on Albert's rating change.
*** Edit *** (I think this is what Blackice meant about the "loss ratio"):
After Turn 9 ratings:
Albert = 20 + .06 = 20.06
Bob = 15 - .02 + .25 + .25 = 15.48
Charlie = 15 - .02 - .25 + .25 = 14.98
Dallas = 15 -.02 - .25 - .25 = 14.48
*** End Edit ***
In total, Albert gains 0.06 ratings points for defeating the much weaker players in the turn 9 power graph for a new rating of 20.06.
Albert is playing in four other games exactly similar to the one above, where he plays against 3 much weaker players than himself. So that now, after the first 9 turns of all of his games,
Albert has a new rating = 20.30 (Differential Based)
(20 + 0.06 + 0.06 + 0.06 + 0.06 + 0.06 = 20.30)
Edit: Without doing the exact calculations for the other players, I can estimate their new ratings assuming that order of the 5 games
-----------------------------
Conclusion:
In the first example with GameLeague Based calculations, Albert has managed to go from a rating of 20 to a rating of 25 by playing in 5 games against players with ratings no higher than 15. This is unfair in my opinion.
In the second example with Differential Based calculations, Albert has gone from a rating of 20 to a rating of 20.30 by playing the mass number of weaker players. This is fair in my opinion.
Last edited by quinns on 25-07-2002 at 04:55
|
|
|  |
 |
|  |
 |
|
blackice
|
 |
Canada where else...
Sep 2000 time: 00:18
|
|
Kralj and? What are you telling me to shut up? That is not going to happen sorry...
I am trying to inform the people here so they can make an informed descision. What have you posted for details so people can make an informed decision?
Last time It is not my system
I find it odd you have read everything but missed that again?
JBTW can you came out with third solution?
Why do you need a third system you have not seen the comparision of these two yet?
It is getting clear a few of you do not want people to see the comparison at all let alone vote on it. Humm wonder why?
On top of that we could see them side by side and start a new thread with the complete story of the two rankings and then offer the choices.
New
Old
Third system to be designed yet
Give the people the chance to see the true pictures then the chance to vote. There are a lot more people here than us five...let them have a chance to vote on all three options. Some people seem to want to just over rule the rest with a third option. Get the true picture out and give the others and opportunity to see them and vote...
Too much politics just get on the the full picture that was omitted. Well whats wrong why not post it Quinn?
You did not offer a complete picture of your system you did of the new one.
Be fair post it lets go...
Last edited by blackice on 25-07-2002 at 03:35
|
|
|  |
 |
|
J Bytheway
|
 |
England
Jul 2001 time: 05:18
|
|
Well, after some research I find that the actual formula is 1/(2+d^2) where d is the difference and ^ denotes exponentation - which makes more sense.
*Here begins the heavy maths *
But it's still a very strange formula - I can't imagine what probabalistic assumtions would give rise to it. Basically if A and B have scores a and b and d=a-b this formula claims that the probability of B beating A is:
1/(2+d^2) for d>=0
and 1-1/(2+d^2) for d<0
this has zero gradient at d=0 which seems exceptionally peculiar. I would have expected a formula more along the lines of:
(1+tanh(d))/2
or:
(pi/2 + atan(d))/pi
Since these have maximal gradient at the origin, but again, these are unlikely to be derived from theory.
Probably you'd actually end up with some formula involving the phi function (phi(d) being the integral from -infinity to d of 1/(sqr(2pi))*e^((d^2)/2), which unfortunately cannot be expressed in closed form) but that's of little use to us.
* Here ends the heavy maths *
But, after some thought I do understand and approve of the application of the probabilities to the manipulation of the scores as described (scores move by half the probability of the observed outcome) since this should award/penalise most for play where the low-ranked beats the high-ranked.
However, the introduction of probabilities is an unnecessary obfuscation of the relevant process, except insofar as it explains the otherwise arbitrary introduction of the '1-' to the defenition of the function used. It might be more sensible, perhaps, to manipulate the function and use it directly to deduce the change made to the scores, rather than including an intermediate step. In this case a function such as that used has some benefits which perhaps explain its use rather than any probability theory.
I can see the Klair-syndrome hidden in this system - it arises from the fact that results on consucutive *9 turns are not independant. Without further study I can't place a cure, but my instict says that it might be a good idea to use a reduced power (change 2 to 1.5 or 1.6), as I suggested above, so that the function decays less quickly - but that might in fact exacerbate the problem. I believe Gav recommended diminishing returns (i.e. you get less for leading if you've been leading for a long time), and that might also help if applied judiciously but my gut warns me off, if only because of the increased administrative burden. Perhaps if a suitable program were written to store the information then it would be plausible.
All in all it's a knotty problem - I'll give it thought as I lie in bed this evening and get back to you tomorrow with any insights I have.
Last edited by J Bytheway on 25-07-2002 at 17:59
|
|
|  |
 |
|
blackice
|
 |
Canada where else...
Sep 2000 time: 00:18
|
|
1. Kralj Matjaz 23.2532 10% wagered=2.3-3.9= 1.6 new ranking 24.8532
2. Faded Glory 22.2950 10% wagered=2.2-2.619= 0.419 new ranking 22.714
3. Darth Viper 10.6760 10% wagered=1.0-1.649= 0.649 new ranking 11.325
4. Nuke Boy 15.0358 10% wagered=1.5-0.97= -0.53 new ranking 14.5058
5. TheBirdMan 27.8815 10% wagered=2.7-0.485= -2.6515 new ranking 25.23
9.7 points wagered total divided by the forumula below:
5..1ST..41%..2nd..27%..3rd..17%..4th..10%..5th..5%
This game is waiting to be ranked so I used it as an example. 1st 2nd and 3rd receive some points be it token points for 2nd and 3rd. 4th and 5th negative points. As you can see award/penalise most for play where the low-ranked beats the high-ranked. Is built into this system also. But unlike the old system the new one may or may not award points to the bottom ranked players. They did not win.
Again here we go making new rules to make a system work maybe. The new system works and awards points for winning. No new rules are needed and you do not have to have a math degree to understand the formula.
John the old system also awards points for second and third and forth if they beat a higher ranked player. I guess that means it is flawed too even more so...Bottom line is I don't get your flawed reasoning since both do it the old system more so...In a five player game with the bottom position being the highest ranked player. Every person above them will get points it guess I am missing the logic here? You dismissed the new system for something the old one does more of?
Maybe you could explain why?
It also awards way more points for doing so and way more negative points for the loser. Look at the blackice example.
The difference is the ease of the new system and the built in no need for rules to create balance and fairness.
Last edited by blackice on 25-07-2002 at 03:50
|
|
|  |
 |
|
blackice
|
 |
Canada where else...
Sep 2000 time: 00:18
|
|
quote: Eh? The old system would never have awarded points to the bottom player, but the new one might if they were ranked sufficiently lowly. |
Oh so it does not award players for beating a higher ranked player?
Or is it only the first placed player that beats a higher ranked player that gets points? If the higher ranked player is last of five players. fourth place gets no points for beating them? they do in fact get points. J. They are awarded one win over the last place player and then three losses for being in fourth. So in each and every 9th ranked turn someone takes 3 losses and one win for fouth place. They also lose points for beating a higher ranked player. The reality is 1st and 2nd get all the awards for beating the Higher ranked player. In the new system 1,2 maybe three and maybe four will get points for beating the higher ranked player. More fair.
quote: Unless the winner is far ahead already in which case they lose points for winning |
Are you refering to LUNG? if so then yes you have top spot you have to play games to keep it. on top of that you have to play at least one higher ranked player to gain points. In Lungs case his remaining game he is way ahead of his opponents so no he will not be rewarded big for beating far lower ranked players.
quote: But that's a good thing, isn't it? |
You mean it is flawed if the new system does it but not if the old one does? Makes no sense still...
quote: Is that the one where he wins 2 games, loses 1 and drops in score? That is primarily due to the falloff speed of the formula used (I presume). If that situation continued then an equilibrium would have been reached with Blackice at some lower score, but still higher than all his competitors, just as it should be. The details of the formula will dictate the position of this equilibrium. I don't see the problem. |
Really the other players would be going up and he down so what you are saying is they meet and all stay the same? How would blackice stay ahead if he losses points for one loss and two wins? Makes no sense.
quote: Ease is nice, but I'd rather have fairness |
The new system is fair the winner gets points as do second and third sometimes. The losers lose points(sometimes depends on the rank of the players)what is not fair about that? makes no sense again.
Quinn where is that complete example? You are not going to post it or what? Do you not think the people should see the two systems side by side in an equal and fair comparision?
This is all talk until we see a clear example of the old system J. could you take the example I just gave and use the old system to show how it works to the other players here? We can see them side by side with the same players as an example. Would that be possible?
Last edited by blackice on 25-07-2002 at 04:40
|
|
|  |
 |
|
quinns
|
|
Thanks for the very reasoned response J Bytheway! You are right about the above formula... I will fix it in the above post (i.e. it is the differential alone squared, without the +2). Regarding "probablity", it was a stretch to use that term because it is an imperical number, but I thought it might help to understand what the formula was doing. Also, I had considered using an exponent of 1.5 or 1.6 instead of 2, but thought it would make the formula too messy. But maybe your right. It would level out the curve somewhat.
Blackice, I would be happy to post the "loss ratio" but I don't know exactly what you mean by that. For example? You mean the number of ratings points that the losers lose? Or the ratio of winner gain points to loser loss points? That ratio is always 1. That is, if Albert gains .02 then Bob loses .02. The ratio = .02/.02 = 1. This is always true. I don't think that is what you meant though when you said "loss ratio". Edit: Ice, I added what I think you meant by "loss ratio". Take a look at my previous post where I show the ratings of Bob, Charlie, and Dallas after the first *9 turn.
Obviously, JBTW has much more knowledge about this subject than I. I await his thoughts on this tomorrow.
Last edited by quinns on 25-07-2002 at 04:59
|
|
|  |
 |
|
quinns
|
|
Ice, it isn't really apples to apples to use the Birdman example you mentioned. At this point, the PBEM ratings are already way out of skew as compared to the old system. In my opinion, there is no possible way that Birdman should be 17 points higher than Darth Viper. I have played both players and know both of their relative playing abilities. At most Darth Viper and Birdman should be within 1 to 3 points of each other.... not 17! See, I would have to use an example BEFORE the GameLeague based system took over in order to compare apples to apples. However, if you really feel it would clarify things for you and everyone else, I can do the calculations if you like. But as I said, I would be using the old system to calculate the already heavily skewed GameLeague based rating numbers. It would not be apples to apples.
|
|
|  |
 |
|
J Bytheway
|
 |
England
Jul 2001 time: 05:18
|
|
quote: Originally posted by blackice
quote: Eh? The old system would never have awarded points to the bottom player, but the new one might if they were ranked sufficiently lowly. |
Oh so it does not award players for beating a higher ranked player?
Or is it only the first placed player that beats a higher ranked player that gets points? If the higher ranked player is last of five players. fourth place gets no points for beating them? they do in fact get points. J. They are awarded one win over the last place player and then three losses for being in fourth. So in each and every 9th ranked turn someone takes 3 losses and one win for fouth place. They also lose points for beating a higher ranked player. The reality is 1st and 2nd get all the awards for beating the Higher ranked player. In the new system 1,2 maybe three and maybe four will get points for beating the higher ranked player. More fair. |
Sorry, I misunderstood you - I thought you meant the bottom player, not just one near the bottom. It is indeed true that If a few low-ranked players beat a sufficiently highly ranked one then all of them will gain, and the highly ranked player will lose a lot. Surely the highly ranked player should lose a lot in this situation, and since the system is conservative (total rank of all players constant) it is inevitable that the other players will rise. Is your concern that too much of this rise is allocated to the lower amongst those lowly ranked players - I can see that this might be a problem.
quote:
quote: Unless the winner is far ahead already in which case they lose points for winning |
Are you refering to LUNG? if so then yes you have top spot you have to play games to keep it. on top of that you have to play at least one higher ranked player to gain points. In Lungs case his remaining game he is way ahead of his opponents so no he will not be rewarded big for beating far lower ranked players. |
This I view as a bad thing - I think you should be rewarded for every victory, no matter how apparently trivial, but that those rewards should be small. If this is what you want then certainly the new system (or something like it) is appropriate.
quote:
quote: But that's a good thing, isn't it? |
You mean it is flawed if the new system does it but not if the old one does? Makes no sense still... |
No, the flaw in the new system to which I was referring in this context was that the very last player (5th of 5, or whatever) can gain points if losing to sufficiently highly ranked players, not the awards to those near the bottom for beating a player who is highly ranked and last.
quote:
quote: Is that the one where he wins 2 games, loses 1 and drops in score? That is primarily due to the falloff speed of the formula used (I presume). If that situation continued then an equilibrium would have been reached with Blackice at some lower score, but still higher than all his competitors, just as it should be. The details of the formula will dictate the position of this equilibrium. I don't see the problem. |
Really the other players would be going up and he down so what you are saying is they meet and all stay the same? How would blackice stay ahead if he losses points for one loss and two wins? Makes no sense. |
No, I mean that he will drop and they will rise until they are a certain distance apart appropriate to this win/loss ratio. The fact that he is losing points for 2 wins/1 loss is essentially because - according to the system - someone with a 2/3 chance of victory should not be so far ahead of his opponents as he is. As his score drops the aqmount by which it drops will slow.
quote:
quote: Ease is nice, but I'd rather have fairness |
The new system is fair the winner gets points as do second and third sometimes. The losers lose points(sometimes depends on the rank of the players)what is not fair about that? makes no sense again. |
If you don't mind situations like that in which Lung found himself (and the converse for very lowly ranked players) then there is nothing wrong with that. That is the only obvious flaw to me (but that doesn't mean there aren't others). If you can live with that then the ease of use almost certainly outweighs any other problems. I'm certainly not going to volunteer to maintain the rankings and so I don't think my opinion carries very much weight, but it was requested and so I give it.
quote: This is all talk until we see a clear example of the old system J. could you take the example I just gave and use the old system to show how it works to the other players here? We can see them side by side with the same players as an example. Would that be possible? |
Yes, but I won't because I don't have a spreadsheet to hand and my graphical calculator is out of batteries . This system does need a calculational aid in excess of Windows calculator to do in any sensible time, which I'll be the first to admit.
The best recommendation I can come up with so far is this:
Use a differential system as before, so if A beats B and d=a-b then increase a by f(d) and decrease b by f(d) where f is the function:
f(d) = { (1/(2+d))/n if d>=0
.......{ (1-1/(2-d))/n if d<0
where n could be 2 for simplicity, but if you wish to avoid Klair syndrome then it might be better to use n equal to the number of times A has beaten B in this game so far (including this one) - but that does of course require storing additional data and I don't think it would be worth it.
I reduced the power all the way to 1, rather than stopping at 1.5 since this avoids the 'messiness' quinns mentions, and simplifies things further.
Though it's purely gut instinct, I think that you should indeed calculate all changes before applying any of them as someone (blackice?) recommended a couple of pages ago - but it probably won't make that much difference so if it would be simpler not to then I wouldn't worry.
In any case, I believe that this is a fascinating subject (ranking theory?) and I think I'll do some additional research into it, though probably not in time to be of any use to you.
I've noticed a mistake in the above post - I confused the probability of A beating B with that of B beating A - I'll fix that.
|
|
|  |
 |
|
quinns
|
|
Alright Blackice, here is the old way of calculating your example (rounding to two decimal places). It took me about an hour of manual work, but in the past the program did all of the work once the *9 finish orders were entered. I hope this clarifies things.
Differential Based Calculation Example
*9 Finish Order:
1. Kralj Matjaz 23.30 (K)
2. Faded Glory 22.30 (F)
3. Darth Viper 10.70 (D)
4. Nuke Boy 15.00 (N)
5. BirdMan 27.90 (B)
K d. F: Prob = 1/(2 + 1.0**2) = .33 --- K is higher than F so Change = .33/2 = 0.17.
K d. D: Prob = 1/(2 + 12.6**2) = .01 --- K is higher than D so Change = .01/2 = 0.01.
K d. N: Prob = 1/(2 + 8.3**2) = . 01 --- K is higher than N so Change = .01/2 = 0.01.
K d. B: Prob = 1/(2 + 4.6**2) = .04 --- K is lower than B so Change = (1 - .04)/2 = 0.48.
F d. D: Prob = 1/(2 + 11.6**2) = . 01 --- F is higher than D so Change = .01/2 = 0.01.
F d. N: Prob = 1/(2 + 7.3**2) = . 02 --- F is higher than N so Change = .02/2 = 0.01.
F d. B: Prob = 1/(2 + 5.6**2) = .03 --- F is lower than B so Change = (1 - .03)/2 = 0.49.
D d. N: Prob = 1/(2 + 4.3**2) = . 05 --- D is lower than N so Change = (1 - .05)/2 = 0.48.
D d. B: Prob = 1/(2 + 17.2**2) = . 01 --- D is lower than B so Change = (1 - .01)/2 = 0.49.
N d. B: Prob = 1/(2 + 12.9**2) = . 01 --- N is lower than B so Change = (1 - .01)/2 = 0.48.
Net Change:
Kralj Matjaz: +.17 + .01 + .01 + .48 = +0.67
Faded Glory: -.17 + .01 + .01 + .49 = +0.34
Darth Viper: -.01 - .01 + .48 + .49 = +0.95
Nuke Boy: -.01 - .01 - .48 + .48 = -0.02
Bird Man: -.48 - .49 - .49 - .48 = -1.96
New Ratings (Differential Based):
1. Kralj Matjaz 23.30 (K) +0.67 = 23.97
2. Faded Glory 22.30 (F) +0.34 = 22.64
3. Darth Viper 10.70 (D) + 0.95 = 11.65
4. Nuke Boy 15.00 (N) - 0.02 = 14.98
5. Bird Man 27.90 (B) -1.96 = 25.94
Last edited by quinns on 25-07-2002 at 21:43
|
|
|  |
 |
|  |
 |
|  |
 |
|  |
All times are GMT. The time now is 05:18. Apolyton Time is 00:18. |
top of page
|
|
|
Forum Rules:
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
|
HTML code is ON
vB code is ON
Smilies are ON
[IMG] code is ON
|
|
|
|
|
|