The blackjack problem

by Adacore • 30 Oct 2008, 17:02 • Journals
I solved it!

I've been having a problem with working out tournament structures for more than 21 teams (hence the name blackjack), but fewer than 32 teams, which result in a minimum of 3 matches per team but don't take too long to run at LAN. It's been puzzling me for more than a month now. Finally, today, inspiration struck and I solved it! Yay!

EDIT: No I didn't. Fail. Dammit. I've thought of another way that does work, but it's nowhere near as elegant. Back to the drawing board...
Comments
22
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ipsOOnnn 30 Oct 2008, 17:05
blackjack @ cc5 ?
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Adacore 30 Oct 2008, 17:06
Nah, just called it blackjack because it only applied for 21 teams or more.
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ipsOOnnn 30 Oct 2008, 17:30
oh:( would be nice blackjack on cc5 though ^^
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SPU9 30 Oct 2008, 17:06
huh

what kind of tournamentstructure?

what about 24 teams and 4 groups a 6 teams = 5 games for each team and playoffs for the best 8
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Adacore 30 Oct 2008, 17:08
Groups of 6 are too big. Results in 15 games per group, 60 games total = breaks the schedule.
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SPU9 30 Oct 2008, 17:13
so if you say minimum of 3 matches per team= groups of atleast 4 teams

mhh mhh let me think....
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Adacore 30 Oct 2008, 17:17
I just realised I failed anyway, so don't bother.

It actually works for 24 teams, but not for 21, 22, 23 which was the real problem. Dammit.
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SPU9 30 Oct 2008, 17:21
so you need a tournamentstructure for 21, 22 or 23 teams with atleast 3 games per team?
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Adacore 30 Oct 2008, 17:31
Yes, I've thought of one idea so far that would work (a variation on my original solution which didn't work):

- Six groups of four, group winners progress to brackets, 2nd and 3rd place teams go to a second groupstage with four groups of three, winners of the second groupstage groups play off against each other to get into brackets.

Substitute the groups of four for groups of three as needed for 21/22/23 teams total.

None of these are ideal though. Four groups of six would be great if we have time/PCs...
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Adacore 30 Oct 2008, 18:02
Another crazy idea that would work - run it like a league, but don't have every team play every other team. Maybe two leagues, so 2 big groups. Each team plays 4 games in their league, or something, then the top 4 teams from each league progress. Not worked out how easy it is to balance that fairly though.
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Viax 30 Oct 2008, 17:29
with less than 24 you should simply have some groups with less teams, otherwise you'll always get fuckups. never heard of an elegant solution for that :-/
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Nellie 30 Oct 2008, 17:29
Post what you've got! Let those of us borer ponder.

Would you consider an unconventional bracket ala the RL WC? Weaker / stronger group -> playoff, allows you to play around with group numbers.
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SPU9 30 Oct 2008, 17:31
some shitstructure:

21 teams:

4 groups a 4 teams
1 group a 5 teams

best 3 of each group proceed = 15 teams @ playoffs
+
4th and 5th of the 5x group have to play a qualimatch for the last playoffspot ;p

would mean that just the last and weakest team of each group drop out after the groupstage.
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Adacore 30 Oct 2008, 17:33
Not a bad idea. Certainly one to put some thought into - thanks!

EDIT: It's borderline on hitting the maximum match limit (as it has a 16 team double elim playoff, which is 30 games total, as compared to an 8 team double elim which is 14 games). Ideally I'd like to stay under 60 matches total and that's 65 (34 from groups, one from 4+5 playoff and 30 from brackets).

With that constraint, it's actually possible to do 21 teams relatively easily using a group of 6 (59 matches total), 22+ doesn't work though (22 is 64 matches).
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zifff 30 Oct 2008, 17:14
2-6 = +1
789 = neutral cards
A J Q K 10 = -1
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vegi 30 Oct 2008, 17:29
tried it on rl casino, no way u can keep the count on a full table unless u trained very very fast counting xD
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zifff 30 Oct 2008, 18:02
you need a gifted mind! (I also suck at counting cards, still after some hours of training ... dealers are way too fast)
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Adacore 30 Oct 2008, 17:51
The reason this is a problem, as those of you with elementary deduction skills may be able to see, is that the ET tournament is looking likely to have something in the range of 20-25 entrants.
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rewuz 30 Oct 2008, 18:11
Beep! Noobbus coming to take you back to school. Get in Adacore!
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BlackJack 30 Oct 2008, 18:37
There I was thinking that it would be a post about me.




:(
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anzz 30 Oct 2008, 18:43
24 teams:
6 groups of 4 teams.
winner of each group -> playoff
the 2 "best 2nd" -> playoff (could be decided by who won the most rounds?) and when to teams who became 2nd have exact the same score, just a decider match for those teams to find out who is the best "2nd"

21/22/23:
4 groups 4 teams
1 group 5 teams
winner of each group -> playoff
all 2nd of each group get to the "pre playoff bracket"

pre playoff bracket:
that are 5 teams (the 5 who became 2nd), so u need 1 extra team. My suggestion, maybe a bit crappy, but just write down the names of each clan who became 3rd in groupstage. And pick one out, with ur eyes closed ofcourse ;-).
So the total is 6 teams now. that are 3 matches -> winner of each match gets to the playoff.

total teams in playoff = 8. (5 group winners + 3 pre playoff bracket winners)


Edit: with 22 teams same procedure, only with 3 groups of 4 teams, and 2 groups of 5 teams. when 23 teams are playing: 2 groups of 4 and 3 of 5 teams.
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