VSK Match Forum

by **euphoria** » 19 Dec 2002 14:32

I understand this will soon come for vsk2, but please do not only create a sum of the points earned in races. Let the ranking be a reflection of the quality of the skipper, not only the quantity of the races he has made, as the vsk1 ranking was. Why not use the chess or backgammon type of ranking, which gives you more points when beating a better ranked
skipper etc.?

by **Men Bret** » 20 Dec 2002 11:08

I'm not a big ranking fan (probably because I never went very high in ranking

). It showed its wrongs effects when it was disabled for a while in VSK1. Players were less agressive and more respectfull of the rules.
So what I think is that ranking should be implemented only if the virtual empire applys the corect rules. Otherwise it will soon be a battlefield out there.

by **euphoria** » 20 Dec 2002 11:20

Good point Vincent!

I then modify my suggestion...
Like in other games, players should be able to choose whether the race should be social or ranking. Simply create two different rooms for races... And as the number of vsk2 players increases, we need more rooms anyway. Can't have hundreds of players in the same room at the same time. Well, you can but it would be chaotic

by **admiral 1** » 04 Jan 2003 18:35

Been playing with ranking till about 1 - 1,5 year1 ago...
exchanging some e-mail with the then vsk team. Had to drop that cause of some new crewmember joing our family.

Basics should still be online most of the time, (doesn't work with NS 6x + , should be okay with IE) just try the link link
'sim sail ladder'
at http://www.admirals.de/virtualskipper/

It should show at the top. It's dynamic so don't bookmark.

It revolves around some formula Keith Suderman (CAN Knot) came up with, borrowed from the international chess federation.

I did some small modifying to be able to compare matchraces with fleetraces etc.

It basically compares skippers' odds of winning with his actual result.

e.g. bad result although high odds for a win gives little points (bad enough may even result in deductions....)
good result against bad odds gives many points.

The odds are based on accumulated points to date of the various participants in a race.

The points are mediated to compensate for the number of boats in a race.

1.stly it matters little how many races you sail.

2. ndly newbies are advanced more promptly then more experienced skipper (newbies have to be evaluated so that they have the right odds put against them)

3. rdly winning 100 times against the same skipper won't help,
as the odds of winning rise with every win, leading to no point
gain after a short while.

By changing the paramaters in the formula the rates of change can be influenced.

The number of points (could call that a rating) translates into a
ranking.

The bigger problem (for a vsk independant ranking, rating or point system) is to get the results in a database.

Keith came up with a real good idea, unfortunatly a bit late for
incorporation in the release version. Basically he suggested that
the race results should be presented to the host in XML format.

I would like to take that further. The host should have to
give an e-mail adress(es) to wich the results are to be be e-mailed. (I think xml format will do just fine).

Receiving an e-mail, extracting the results and dumping those in a database, execute some code etc. shouldn't be much of a problem for most 'clubs, organisations, committees etc.' and would allow the automatisation of tournaments, rankings and ratings etc.

by **euphoria** » 04 Jan 2003 19:22

That's just great work, Theo. I was talking with Luc Fresel 3 years ago about a similar concept, and he promised it would come with the next version of vsk... He's no longer in the team, but I hope it's taken care of by the new staff in Duran.

At least I know Adrienne from Duran is reading the suggestions made in this forum.

Harald

by **euphoria** » 07 Feb 2003 14:53

The points arrived with Patch 1.3, but not yet a ranking based on the points. And I hope they keep it that way, as a sum of points is just not interesting at all. Please Duran, your game deserves something better!

Harald

by **Aeolus** » 07 Feb 2003 23:34

I agre with you Harald. The fact that we do a lot of team racing ruins the point/race ratio as first place boat usually slows others down and ends up crossing middle. This isn't a ranking system, this is mearly a system that shows you how much others are online.

Tony

by **euphoria** » 25 Feb 2003 01:48

I have created a rating system (or rather modified the one from 3 years ago) of which I hope Duran will adopt. The client forward all necessary information as it is now (only the race positions that is...), so it's only a question of the server performing a database lookup to receive opponents rating and a couple of formula calculations before adding the points to the user file.

Here's an Excel file as an example on how it works. I will put the formulas on the web/forum for you with no Excel access later.

Rating.xls

Harald

by **TeamNZ** » 25 Feb 2003 02:18

euphoria wrote:I will put the formulas on the web/forum for you with no Excel access later.

of which i,m one of

for the life of me, i cant rememeber where my office cd is ???

by **euphoria** » 25 Feb 2003 12:50

Here's an example from the excel sheet:<pre>
Ro 1500 Current rating
Length 3 Lengt of course (1-4 for 'short' - 'very long')
Laps 2 WP No. of laps
R1 1700 24 % Rating of opponent 1 and probability to beat him/her (WP)
R2 1300 76 % Rating of opponent 2 and probability to beat him/her
R3 1200 85 % Rating of opponent 3 and probability to beat him/her
R4 1100 91 % Rating of opponent 4 and probability to beat him/her
R5 1600 36 % Rating of opponent 5 and probability to beat him/her
R6 1500 50 % Rating of opponent 6 and probability to beat him/her
R7 1900 9 % Rating of opponent 7 and probability to beat him/her
Pos 2 Actual position in race
EPos 4.3 Estimated position
K 18.2 Rating points factor, varying with length and laps (10-32)
NB 8 Number of boats in the fleet
Points 5.9 Points gained/lost
Rn 1506 New rating</pre>
Here's the text version of the formulas:

Diff - Difference in rating between you and an opponent (Ex: Ro-R1)

WP(Diff) = 1/(1+10^(-Diff/400)) <-- To be calculated for all opponents in the fleet
Epos = 1+(1-SUM(WP)/(NB-1))*(NB-1)
K = (10*SQRT(24)-32+SQRT(Length*Laps)*22)/(SQRT(24)-1)
Points = K*(Epos-Pos)/(NB-1)
Rn = Ro+Points

Length 4 equals 6 in the formula, since 'very long' is 6 times longer than 'short'

Initial rating for all boats is 1500. The more rating points, the better skilled sailor. The calculations are based on the chess rating, of which has been adopted (and modified) by hundreds of online games on the internet.

Points calculations for a race are based on the strenght of your opponents. If you beat a better skipper, you will receive more points than if you beat a skipper with less rating points than you have. If you loose to a better skipper, you will not loose as many points as you would if you lost to a worse rated skipper.

As all skippers start at 1500 points, it will take a while until it's stabalized. If the VSK2 pool was a static group that doesn't improve it's sailing skills, all player ratings would more or less stabalize at certains rating levels, of which actually reflects the skippers skills (the skippers performance is assumed to follow a normal distribution function, therefore the probability to win (and estimated position) is based on this common statistical function). If you improve your skills, then it wont take many races until your rating reflects your new "level".

It may seem strange that you only have to have to enter your position to have your points calculated. But it doesn't matter if you beat a better skipper and loose to a worse skipper rather than the oposite. The points will be the same regardless of the other boats order. If you calculated the points as a sum of victories/losses to all the other skippers individually, the result would also have been excactly the same. It's just mathematical/statistical wonders ;-)

I have calibrated the formula to give the same maximum possible points for all race sizes. Even if you beat more skippers by winning a 8-boat race than a 4-boat race, it's taken into account that luck (and bad luck) is a greater factor in bigger fleets.

The maximum possible points to acheive is 10 for the shortest length/lap combination, and 32 for the longest. The longer the race is, it's more likely that the better skipper will win.

As you loose points by performing worse than the estimate, this will probably prevent skippers from disconnecting as often as they do now. If you get kicked out of the game... well, that's just bad luck and is hopefully not happening very often so that it will affect your rating signifficantly. If there's only a disconnection between the players only, and they all register results to the server (but some different), it should give benefit of the doubt and base the calculations on the results from your own client.

Please comment or raise questions before this is forwarded to Duran.

Harald

by **Aeolus** » 25 Feb 2003 14:51

As you know Harald I'm not long winded in these forums. That being said, awesome idea. :grinning: I think it would be fantastic if we could get away from the point system and get into a rating system. The current system doesn't really show us anything because if a skipper only really likes to match race, the most he will ever get for a win is 2 points. Even if he won every race, with the current system it would appear that he isn't that great.

Tony

Edited By Aeolus on 1046177513

by **euphoria** » 25 Feb 2003 15:34

If (when...) they implement a rating system rather than a "No. of race"-meter, they should make multiple rankings:

Seperate for fleet races and match races. Match is a different game...
Seperate for each of the 4 boat types.
That's 8 different titles to chase. Alot of fun...

What about Expert/Pro modes. Different rankings for these two? Maybe not. At least it should be possible to choose to run games that doesn't count for the ranking. Or maybe Beginner/Intermediate modes can take care of that. But then we have to sail at those levels at ITBYC...

Harald

by **The Nude** » 25 Feb 2003 17:03

Sounds brilliant, execent work harald.

andy - the nude

by **euphoria** » 25 Feb 2003 17:45

I can add that the sum of points scored in each race is allways 0 (zero)! So the ratings will not grow into the sky (or drop below 0). They will more or less reach a marginal value of which it will be hard to go above/below. The average rating for the entire players pool will allways be 1500.

I was also thinking about disconnections. If players disconnects, they should be ranked in the order they are disconnecting. If you're the only skipper left in a race, you shouldn't have to finish to score a win. If it's a sync problem, and boats appear to head straigth into the horizon, then the finish time should be used to classify the boats.

Harald

by **admiral 1** » 25 Feb 2003 22:16

obviously this is more or less the way to go.

We can differ on wich parameter to take in account but basically a weighted score is used in any ranking/rating system.

I don't see a reason why a long race should be weighted differently from a short race, unless you want to take the size of a win/loss in account.

Thing is you want to compare everybody with everybody.... for starters. So someone racing only melges can/will be compared with someone racing only acc etc.. There are numerous possibilities. The building of the rating dynamically needs alot of computing power, so should opt for static tables, and still keep all the race data so you can build a ranking on any parameter you want.

I'm thinking along the lines of having a apache/php/mysql on windows solution (will run on linux boxes too) that can be run by anybody who want or needs a ranking/rating for vsk.

Based on what the score****.txt files contain i conclude that all neccesary data is already collected.

So if you want Harald, i can send you the code, database etc.
to play around with. Only needs to be ported to ASP and or Msql i think is what the vsk servers run on.

Or you'll have to wait till i'm done porting

that will take a while....

As i first want to be able to read the score****.txt 's into the database, every race has a unique identifier so it can't be submitted double. Eventually all that wouldbe needed to do is have the scores mailed to the server loading the database.

When vsk wants to do rating /ranking similarly maybe i should send Adrienne the scripts ? and actuallly someone is going to do something with it....

again to see it life http://www.admirals.de/virtualskipper/
and click the apropriate link

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