Double Elimination

[peterwaller]

I think I have finally worked out how to do this with varing numbers of entries. Basically the first rounds are based on groups of 8 robots. This means that for upto 32 entries there are 4 groups and the final consists of 4 group winners and 4 group runner ups. between 33 and 64 you have 8 groups and the final consists of 8 group winners and 8 group runner ups. Where ther there are less that 32 or 64 the number of entries in the groups is reduced as evenly as possible over the groups. ie. for 53 entries the first 5 groups have 7 robots and the last 3 have 6 robots. I have generated a flow chart for 8, 7, 6, 5, 4 robot groups showing the byes and a chart for a 4 group or 8 group final. This means that there need be only one draw at the beginning and by putting robots from the same team or using the same frequency into different groups you avoid clashes at least until the final stages. It sound rather complex but once you have the charts you just fill in the drawn robot names and from then on fill in the results as directed and it becomes obvious who fight who. At the end of the group stages the winner and runner up of each group is placed in the appropriate box in the 4 or 8 way final chart and continue as before.

[Craig_Anto3]

errr yes Pete...... i think u need to get out more mate

on a serious note thou its what i want to do for aws18 althou i may have a way to make sure everyone gets a min of 3 fights but that does depend on numbers

but a side from that well done old timer

[Remote-Controlled Dave]

I kind-of understand it all Pete, but when you get 7 bots in a group, there's still one left over isn't there? Unless you mean everyone in the group fights everyone else in the group and then the winner and runner-up go through, but that's a hell of a lot of fights isn't it?
Please explain if I'm wrong. Or maybe put your flow chart up?

[Simon Windisch]

That sounds a bit like the league method we use at RRC. I've got a sample set of scoring sheets http://windisch.co.uk/electra/howto/Sco ... sheets.htm here.

You can make these sheets up for any number you like in a similar fashion to Pete's system. I now have sheets for 10, 12, 14, 16, 18, 20 & 24 robots. The only problem is that I have to print out the sheets the night before, and we never get exactly the number of robots turning up that we thought we were going to.

Simon

[BeligerAnt]

At least while Pete's doing this he's not improving his robots or practicing his driving!

It sounds OK, and I think byes are the only way to do it. This is not a league system. It works well and guarantees at least 2 fights for everyone, but it is a bit hard to follow until you've worked it out for yourself. (I'm sad enough to be in that position!)

For a group of 8 entrants:
You start with 4 1-on-1 fights. All the winners go into one group (A) and all the losers go into another group (B). These groups then fight 1-on-1 and the losers from group B go out (now having lost 2 fights). The winners of group A go into group D. The winners of group B and the losers of group A (all played 2, won 1, lost 1) go into a group (C) together and fight 1-on-1. The losers go out (having now lost 2 fights). The winners from group C now fight 1-on-1 (group E) with the losers going out and the winners going to group F. Meanwhile group D fight 1-on-1 with the winner going into the quarter finals and the loser going out. Group F now fight 1-on-1 with the loser going out and the winner go into the quarter finals.

Clearly, this is complicated, and only works for 16, 32, 64 entries. The only way to make it work for other numbers is to use byes in the early rounds. I'm not really a fan of byes, but it might be a way to ensure people get more than one 10-second fight at an AWS. One potential problem that comes to mind is byes "propagating" into the later rounds, do you have a fix for this Pete?

A league system works well for upto about 20 entrants, but probably needs an even number and when the numbers get above about 20 the number of fights gets too big.

The biggest problem is that you never know how many entrants you will really have until the last minute (and then it can still change!). I tried to write a PC program to handle it, but gave up as a pen and paper are so much more flexible!

[josh]

simon- oooh thanks simon ill use that at ickenham if we get it

[peterwaller]

By spreading the byes evenly you only get byes in the first round but as there is no loser from the bye the adjacent loser also has one less fight.

[Raizor]

Not necessarily pete,

If the bye is considered to be a robot then this can be avoided i.e.:
Militant draws a bye in the first round, although no match takes place it is considered that militant defeates they bye and continiues on in the winners bracket and the bye goes into the losers bracket. THere fore whoever would have faced the loser of the militant vs bye fight now takes on the bye and moves on to the second round of the losers draw

Does tht make sense to you guys, I know what i want to say but i dont know how to portray it clearly

Regards
Ian

[Remote-Controlled Dave]

It makes sense to me Ian, as does Simon's method.

What about the method they use in America, where everyone fight's in the first round, the winners going onto the winners bracket and fighting til there's one left, and losers going into the losers bracket and fighting til theres one left. Winner of winners then fights winner of losers for the title. Byes would be used as Ian says.
This seems to work well for their events, and ensures each bot 2 fights at least.

[Andrew_Hibberd]

The only problem with that method Dave is that teams tend to be the same (umm can't think of the right word, something like) goodness. So teams are more likely to face each other, although looking at other methods this will proberly happen anyway. So it could be done, if you just avoid the clashes.

At aws14 there was 4 'pools' of 8, but i get lost as to what happened after the second round. The good thing that came out of it was if you put one robot in each team in each quater then they will have to have 2 fights where they don't face each other.

I feel sorry for craig who has to choose which one to use