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        Arimaa >> General Discussion >> World Championship Player Fund
        
(Message started by: Janzert on Aug 16^th, 2014, 2:06pm)

Title: World Championship Player Fund
Post by Janzert on Aug 16^th, 2014, 2:06pm

An anonymous donor recently approached me wanting to sponsor a player's world championship fee via choosing a random player from the weekend tournament players. Since I quite like the idea, with the encouragement of that initial donor, I decided to try implementing an open way for community members to fund player entry fees.

The fund will take donations of Arimaa points and then shortly after the the WC registration opens will have a random drawing of players that have applied. Players who have played more weekend tournament games will be given a higher chance of being chosen.

You can find the all the details on the fund wiki page (http://arimaa.com/arimaa/mwiki/index.php/2014_Championship_Player_Fund).

I'd love to hear any feedback and thoughts.

Janzert

Title: Re: World Championship Player Fund
Post by Janzert on Sep 22^nd, 2014, 2:21pm

To make the selection process of the beneficiaries verifiable I am planning to use the script at https://github.com/Janzert/tournament_tools/blob/master/random_choice.py.

The plan is that I will generate a random seed before the candidates apply to the fund. I will keep the seed secret while posting the hash of the seed. After selections have been made I will post the seed as well and it can be verified that the seed was pre-generated and was used for the selections.

If no one finds a flaw with the plan or implementation, I will publish a seed hash in the next couple of weeks.

Janzert

Title: Re: World Championship Player Fund
Post by harvestsnow on Sep 22^nd, 2014, 11:41pm

The limiting factor will be the predictability of the choice file. I hope we have a lot of tournaments after you publish the hash. :)

Title: Re: World Championship Player Fund
Post by Janzert on Sep 23^rd, 2014, 10:01am

on 09/22/14 at 23:41:27, harvestsnow wrote:

The limiting factor will be the predictability of the choice file. I hope we have a lot of tournaments after you publish the hash. :)

I'm not sure what sort of attack you're looking at, but for any of the ones I've come up with I'm not sure how number of tournaments makes any difference?

The two attack sources I've thought of are, first a candidate or other outside person trying to influence who is picked and second is myself ensuring certain candidates are picked. The first is defeated by not divulging the random seed until after the selection process and the second by forcing me to pick a seed before the candidates are known.

In any case I don't think there is a reason not to publish a seed hash now. The only reason this should change is if someone comes up with a problem that requires changing either the way the seed is generated, or the way the seed is hashed.

seed_hash: 821c5114681a1430953066e83b53e338f9859fa7

Janzert

Title: Re: World Championship Player Fund
Post by harvestsnow on Sep 23^rd, 2014, 11:04am

I was thinking of the second source. Even if we don't know who the candidates will be, we can make guesses based on the players activity (or even discreetly probe the potential candidates). Then choose a seed that will shoot several times in the desired area, or a little below. At least that's the best attack I can think of.

I was hoping we'd have enough tournaments to make the weights attributed to the players totally unpredictable. But that's not very realistic :P

Title: Re: World Championship Player Fund
Post by aciliomendes on Sep 23^rd, 2014, 12:55pm

Use the hash of the choice file as the seed.

The choice file must be the list of players and weights (number of participation on weekend tournaments?) in a publicized canonical format.
Additionally, the players could inform a string upon application to be concatenated to the choice file and for later verification.

Assuming the safety of the number generator and of the hash function, an attack would need a collusion of applicants.

Edited for clarification.

Title: Re: World Championship Player Fund
Post by Janzert on Sep 23^rd, 2014, 10:59pm

on 09/23/14 at 11:04:46, harvestsnow wrote:

This seems like it would depend on being very accurate in predicting the eventual list of candidates. If I count correctly last year there would have been 28 of the WC players eligible to apply, of those 24 are eligible this year. There are another 29 eligible players that have participated in the weekend tournaments. Finally of course all the players who have not played in either. Of the WC players last year 2 joined in November*. I believe that is just too much variability to get an accurate enough list at this point.

Having said that another way to mitigate this would be to add in another source that can't be predicted, but will be reliably available at and after the time of the selection. How about the closing price of the Dow Jones Industrial average on December 1st as published at Yahoo Finance (http://finance.yahoo.com/q/hp?s=^DJI+Historical+Prices)? Specifically taking price in cents (so it's an integer) and adding it to the chosen seed.

Janzert

* Another 3 actually joined in December, which kind of amazes me every time I think of it. Also of the 44 players 11 of them, or a full quarter, joined in the preceding 12 months.

Title: Re: World Championship Player Fund
Post by Janzert on Sep 23^rd, 2014, 11:01pm

on 09/23/14 at 12:55:21, aciliomendes wrote:

Under this method, the last applicant can choose who is selected.

Janzert

Title: Re: World Championship Player Fund
Post by Janzert on Sep 23^rd, 2014, 11:05pm

The fund balance gains another 1000 points and now has a total of 4500 points. This should pay for 4 player entries.

Janzert

Title: Re: World Championship Player Fund
Post by browni3141 on Sep 24^th, 2014, 1:29pm

What will happen if one winner doesn't want to participate in the WC? I don't know if it's already on the wiki. It's not loading for me right now :(
I got this:
Unexpected non-MediaWiki exception encountered, of type "PDOException"
exception 'PDOException' with message 'There is already an active transaction' in /home/arimaa/public_html/arimaa/mwikiSrc/mediawiki-1.19.0/includes/db/DatabaseSqlite.php:638
Stack trace:
#0 /home/arimaa/public_html/arimaa/mwikiSrc/mediawiki-1.19.0/includes/db/DatabaseSqlite.php(638): PDO->beginTransaction()
#1 /home/arimaa/public_html/arimaa/mwikiSrc/mediawiki-1.19.0/includes/objectcache/SqlBagOStuff.php(173): DatabaseSqlite->begin('SqlBagOStuff::s...')
#2 /home/arimaa/public_html/arimaa/mwikiSrc/mediawiki-1.19.0/includes/parser/ParserCache.php(235): SqlBagOStuff->set('wikidb:pcache:i...', Object(CacheTime), 86400)
#3 /home/arimaa/public_html/arimaa/mwikiSrc/mediawiki-1.19.0/includes/WikiPage.php(2924): ParserCache->save(Object(ParserOutput), Object(Article), Object(ParserOptions))
#4 /home/arimaa/public_html/arimaa/mwikiSrc/mediawiki-1.19.0/includes/PoolCounter.php(187): PoolWorkArticleView->doWork()
#5 /home/arimaa/public_html/arimaa/mwikiSrc/mediawiki-1.19.0/includes/Article.php(587): PoolCounterWork->execute()
#6 /home/arimaa/public_html/arimaa/mwikiSrc/mediawiki-1.19.0/includes/actions/ViewAction.php(40): Article->view()
#7 /home/arimaa/public_html/arimaa/mwikiSrc/mediawiki-1.19.0/includes/Wiki.php(484): ViewAction->show()
#8 /home/arimaa/public_html/arimaa/mwikiSrc/mediawiki-1.19.0/includes/Wiki.php(278): MediaWiki->performAction(Object(Article))
#9 /home/arimaa/public_html/arimaa/mwikiSrc/mediawiki-1.19.0/includes/Wiki.php(593): MediaWiki->performRequest()
#10 /home/arimaa/public_html/arimaa/mwikiSrc/mediawiki-1.19.0/includes/Wiki.php(503): MediaWiki->main()
#11 /home/arimaa/public_html/arimaa/mwikiSrc/mediawiki-1.19.0/index.php(58): MediaWiki->run()
#12 {main}

Title: Re: World Championship Player Fund
Post by Janzert on Sep 24^th, 2014, 2:26pm

on 09/24/14 at 13:29:49, browni3141 wrote:

What will happen if one winner doesn't want to participate in the WC?

There isn't anything explicitly covering this right now. I did make the application period only 2 weeks long to try and avoid the case of someone applying but then losing interest before the tournament came around.

Janzert

P.S. I'm see the same wiki error right now.

Title: Re: World Championship Player Fund
Post by aaaa on Sep 24^th, 2014, 5:39pm

A simple solution would be to randomly shuffle a list of all the contestants, where each one occurs as many times as their respective weight, remove the latter duplicates, and then publish it as the order in which the free entries can be claimed.

Title: Re: World Championship Player Fund
Post by Janzert on Sep 24^th, 2014, 9:05pm

on 09/24/14 at 17:39:44, aaaa wrote:

I'm pretty sure that list shuffling is equivalent to running the current program with the number of selections set to the number of candidates. I'm not sure how to handle claiming an entry though. I really don't want to leave people hanging wondering if they are going to get an entry or not.

Also with the short time between application and the drawing I really don't expect people changing their mind in that time to be a large problem. Maybe I should add an explicit confirmation step after winning though?

Janzert

Title: Re: World Championship Player Fund
Post by Janzert on Oct 23^rd, 2014, 8:16pm

The fund balance is now at 5500 Arimaa points.

I've also added a confirmation step from beneficiaries after selection is done and filled out details of player selection on the fund page.

Janzert

Title: Re: World Championship Player Fund
Post by Janzert on Nov 18^th, 2014, 9:48pm

Thanks to lightvector adding 2000 points and a few more anonymous donors the total balance is now at 8250 Arimaa points.

Janzert