Volleyball Champions League

Oh, you didn't know volleyball had a champions league too?
There are a lot of champions leagues out there, all hoping to emulate the success of the famous one, European soccer's biggest event for clubs. North America, Asia, Africa, and Oceania have soccer champions leagues of their own. (South America's carries a different name, the Copa Libertadores.) There are champions leagues for 20/20 cricket, team handball, table tennis and roller hockey. And most of these events also have women's equivalents.
The volleyball champions league is under way now. The men's event starts with 24 top club teams, three each from volleyball powers Russia and Italy, two from Germany, Belgium, France, Poland and Greece and one from Austria, Bulgaria, Romania, Spain, Turkey, Serbia, Slovenia and Montenegro.
The teams are divided into six groups of four, and, as in the famous champions league, play each other home and home. The top two teams from each group advance, plus the best third place team..
Whoa there! That's 13 teams. How are we going to get from 13 teams down to one?

As you know, volleyball isn't nearly as popular as soccer. The soccer Champions League final could sell out anywhere in Europe no matter who was playing. But getting people to turn up for the volleyball Champions League final at a predetermined neutral site would be just too difficult. So after the group stage, the organizers pick one team to be the host, and that team gets a double bye all the way to the finals. The remaining 12 teams are reduced first to 6 and then to 3 by home and home playoffs. The survivors join the lucky host in a single-elimination final four.
The women's tournament this year is similar, though smaller. Only 20 teams are entered, so there are five groups of four. The top two in each group and three best third places advance.  If it seems a little lame to you to play a whole group stage just to cut a field from 20 to 13, consider that in 2009-10 there were only 16 teams involved: four groups of four. The top three in each four team group advanced. And Metal Galati of Romania advanced as the best fourth-place team. Yes, a last-place team went on to the next round (They didn't win.)
Is there the equivalent of a UEFA Cup or an NIT for volleyball teams not good enough for the big show? There are two of them: the CEV Cup and the even less prestigious Challenge Cup. Sadly, they provide little fodder for devotees of sports systems and structures; they are both straight knockout tournaments from beginning to end.