The "groups of anglers" are known as "Sections" in a match. Usually somebody on an end peg tends to do alot better.
For example 6 sections of 8 = 48 anglers in total.
Each angler is in a section, they are competing against the other anglers in their section to win their section money prize and usually the 3 heaviest catches from the match get 1st, 2nd and 3rd cash prizes....but an angler who is in the ranks of 1st, 2nd or 3rd cannot win their section so the section money then goes to the person who was second....but say if 1st and 2nd in the section was in the overall 1st and 2nd position the section money then goes to the person in 3rd place and so on.
But in team events each team may have 6 anglers in, again the same cash prise rules above apply but depending on their section ranking leads to points which are all added up which forms a fishing league. Sometimes the points can be different....1st place gets you 1 point through, 2nd = 2 points, 3rd=3points etc.....or sometimes the other way around so 1st gets you 10 points, 2nd=9points, 3rd=8points untill you get to 1....and everybody else who weights in gets 1 point, anybody who doesnt catch gets 0 points.
I'm still learning the ropes with all this as you can imagine it's quite complicated!
GE