Hi all, anybody knows or could point me in the right direction to an
algorithm to get tournament pairs like
a football tournament or so?
Is there any Ruby Quiz that solves this problem?
Eduardo Yáñez Parareda wrote:
Hi all, anybody knows or could point me in the right direction to an
algorithm to get tournament pairs like
a football tournament or so?Is there any Ruby Quiz that solves this problem?
You say 'an algorithm' like it's calculating something... I think you
just mean a system to chart the progress, no? The difference being
that one predicts the pairs according to data, and then other merely
plots the current situation.
···
--
Posted via http://www.ruby-forum.com/\.
Does this help?
The cyclic algorithm seems easy enough to implement.
···
On 8/30/06, Eduardo Yáñez Parareda <eduardo.yanez@gmail.com> wrote:
Hi all, anybody knows or could point me in the right direction to an
algorithm to get tournament pairs like
a football tournament or so?
Sort of:
Ruby Quiz - Pinewood Derby Chart (#56)
It wasn't a popular quiz, but there does seem to be some interest in do one along the lines you laid out here. Write it up and I will run it.
James Edward Gray II
···
On Aug 30, 2006, at 5:20 AM, Eduardo Yáñez Parareda wrote:
Hi all, anybody knows or could point me in the right direction to an
algorithm to get tournament pairs like
a football tournament or so?Is there any Ruby Quiz that solves this problem?
Can I call a method defined in ruby script from a
C code by just loading the script.
My C snippet looks like:
ruby_init();
ruby_init_loadpath();
rb_load_file("c.rb");
rb_funcall(self, rb_intern("my_rout"), 0);
The ruby script c.rb has a single method defined:
def my_rout
puts 'I am the king'
end
When I execute it gives me the following error:
c.rb:13: [BUG] Segmentation fault
ruby 1.8.1 (2003-12-25) [i686-linux]
Killed
Regards,
Saumya.
You say 'an algorithm' like it's calculating something... I think you
just mean a system to chart the progress, no?
No, I mean 'something' that make pairs of teams to make a tournament
calendar.
Well, I know it isn't easy, I wanted to do it dynamic but finally I
think it's better to do some lookup tables with the fixtures will be
played for 4 teams, 6 teams, 8 teams and so on.
This is a system, mainly used by chess players, called Monrad.
Example: 100 players, 10 rounds.
The players are sorted according to their score, after every round.
Players are paired from the top.
Two players can only meet once.
The clever reader should here realize the fact that backtracking
sometimes is necessary at the end of the list.
···
-----------------
There is another system called Blocksort, used at least once in a big
table-tennis tournament. If A beats B and B beats C, then A is
considered to beat C as well. The problem with this approach is: you
don't know how many rounds are needed.
-----------------
Maybe this is something for Ruby Quiz?
--
Posted via http://www.ruby-forum.com/.
Does this help?
Yes!
Round Robin Tournament Scheduling
The cyclic algorithm seems easy enough to implement.
This is enough for me, a very easy algorithm which is what my simple game needs.
It wasn't a popular quiz, but there does seem to be some interest in do one along the lines you laid out here. Write it up and I will run it.
How should I do that? Writting general ideas is enough?, Should I write a complete story like
quiz you told me iwth examples and so on?
Eduardo Yáñez Parareda wrote:
You say 'an algorithm' like it's calculating something... I think you
just mean a system to chart the progress, no?No, I mean 'something' that make pairs of teams to make a tournament
calendar.
Well, I know it isn't easy, I wanted to do it dynamic but finally I
think it's better to do some lookup tables with the fixtures will be
played for 4 teams, 6 teams, 8 teams and so on.
Hmmm ... sounds like a Ruby Quiz to me. 
Somebody else was looking for something like this a month or three ago, and we had a number of people propose algorithms. I'd say search the maillist archives for "tournament".
···
On Aug 30, 2006, at 4:40, Eduardo Yáñez Parareda wrote:
You say 'an algorithm' like it's calculating something... I think you
just mean a system to chart the progress, no?No, I mean 'something' that make pairs of teams to make a tournament
calendar.
Well, I know it isn't easy, I wanted to do it dynamic but finally I
think it's better to do some lookup tables with the fixtures will be
played for 4 teams, 6 teams, 8 teams and so on.
They use this kind of this in Bridge tournaments as well, but call it a
"Swiss". Swiss systems work well for a very rough sort, but there are two
main issues.
1. If there are too many rounds, the movement will 'over swiss' since most
people are already in more or less the correct order, so the rounds would
need to be carefully balanced. Over swissing means that weaker players get
"sucked up" into the top of the draw, since the top players have already
played each other - at that point it shifts to a game of which top players
are best at beating up weaker teams / players.
2. The other issue is that Swiss tournaments are pretty bad at picking the
exact best player / team because some good teams might play a harder set of
players during the rounds etc.
Most of the time in Bridge the tournaments are run through a Swiss with a
knockout series following for the top (eg) 8 or 16 teams / players, and
using longer / more matches. Swiss works well when the field is too large
for a round robin, but it works best if you can seed the top 10% or so of
players and match them against non-seeds for the first round - but it should
only be considered as a compromise.
Single or double round robin is the best if you can afford n(n-1) rounds,
another option is pure knockout (Wimbledon), or knockout with a repecharge
(also used a lot in sports).
Ruby content of this mail: 0
Cheers,
ben
···
-----Original Message-----
From: list-bounce@example.com
[mailto:list-bounce@example.com] On Behalf Of Christer Nilsson
Sent: Wednesday, August 30, 2006 11:19 PM
To: ruby-talk ML
Subject: Re: Pairs tournament algorithmThis is a system, mainly used by chess players, called Monrad.
Example: 100 players, 10 rounds.
The players are sorted according to their score, after every round.
Players are paired from the top.
Two players can only meet once.
This is enough for me, a very easy algorithm which is what my simple game needs.
Umh... well, not enough really, I'll have to make some changes to the results, but it's a
good approximation of what I need.
Quizzes are 99% more likely to run if they are all thought out when they get to me, so preferably the latter. I always give feedback on what I see though, so it's fine if you send me a first draft and we back-and-forth it a little.
James Edward Gray II
···
On Aug 31, 2006, at 6:20 AM, Eduardo Yáñez Parareda wrote:
It wasn't a popular quiz, but there does seem to be some interest in do one along the lines you laid out here. Write it up and I will run it.
How should I do that? Writting general ideas is enough?, Should I write a complete story like
quiz you told me iwth examples and so on?
Hmmm ... sounds like a Ruby Quiz to me.
Yes, it's a good candidate to Ruby Quiz. You have to make pairs of
teams, but a team might not
play two weeks at home one after the other.
You could make it more harder if you assign weights to teams, and
doesn't mix teams with
similar weights at first weeks.
I think there are implementations in Perl (Best Pairs or something like
that...) but I don't like Perl :).
Scrabble too, where it's known variously as "Australian Draw" and
"King of the Hill with no repeats"
martin
···
On 8/31/06, Ben Nagy <ben@iagu.net> wrote:
> -----Original Message-----
> From: list-bounce@example.com
> [mailto:list-bounce@example.com] On Behalf Of Christer Nilsson
> Sent: Wednesday, August 30, 2006 11:19 PM
> To: ruby-talk ML
> Subject: Re: Pairs tournament algorithm
>
> This is a system, mainly used by chess players, called Monrad.
>
> Example: 100 players, 10 rounds.
>
> The players are sorted according to their score, after every round.
> Players are paired from the top.
> Two players can only meet once.They use this kind of this in Bridge tournaments as well, but call it a
"Swiss". Swiss systems work well for a very rough sort, but there are two
main issues.
Somebody else was looking for something like this a month or three ago, and we had a number of people propose algorithms. I'd say search the maillist archives for "tournament".
Thanks Dave, I'm going to search it....
Eduardo Yáñez Parareda wrote:
Hmmm ... sounds like a Ruby Quiz to me.
Yes, it's a good candidate to Ruby Quiz. You have to make pairs of
teams, but a team might not
play two weeks at home one after the other.You could make it more harder if you assign weights to teams, and
doesn't mix teams with
similar weights at first weeks.I think there are implementations in Perl (Best Pairs or something like
that...) but I don't like Perl :).
You can make the requirements general enough for this sort of thing that
you end up with a combinatorial optimization problem that could be
NP-complete. I recall about 20 years ago, a lot of research went into
airline crew scheduling, for example. Then again, if you make it too
simple, it isn't much fun. I haven't yet submitted either a problem
or a solution to a Ruby Quiz, but I'd sure take a shot at this one.