How to create tournament bracket

Question

I'd like to create a tournament bracket using Mathematica. I've looked around online, but haven't found any examples yet. Can someone show me how to do this? Specifically, I'd like to have a (somewhat) arbitrary number of participants in a double-elimination bracket.

Edit by belisarius

An example of a double elimination bracket follows

Each team has to be beaten twice to be eliminated. There are a winners and a losers circuit, and when a team loses a match in the winner's side, it enters the losers circuit in an appropriate place, so not to be confronted with past competitors.

Answer 1

Here a basic idea for starters. I use a binary tree which is visualized with TreeGraph. A custom EdgeShapeFunction takes care of the right-angled edges. I leave further customizing of the labels and the rest of the tree as an exercise to the reader.

tree = Flatten@
   Table[{i \[UndirectedEdge] 2 i, i \[UndirectedEdge] 2 i + 1}, {i, 1, 2^4 - 1}];

start = RandomSample[CountryData["EuropeanUnion"], 16];

tournament= Reverse@Flatten@NestList[
     Flatten[(Function[{win}, RandomSample[win, 1]] /@ Partition[#, 2])] &, start, 5];

TreeGraph[
  tree, 
  VertexShape -> 
     (#1 -> 
       Graphics[Style[Text[#2], 14], PlotRangePadding -> 0.2, 
                ImageSize -> 1.5 {40, 15}
       ] & @@@ ({Range[31], tournament}\[Transpose])
     ), 
  VertexSize -> 1, EdgeStyle -> Blue, 
  EdgeShapeFunction -> ({Line[{#1[[1]], {#1[[2, 1]], #1[[1, 2]]}, #1[[2]]}]} &)
]