Not in the middle ! Upstream swim you have first chance of intercepting /catching Barbel that are moving downstream , vice versa on the downstream swim . In match fishing drawing a downstream end peg is often seen as good as any fish moving upstream into the length meet your bait first , presuming of course that there isn't anyone further downstream who has already got their attention . I think disturbance can also be a factor , three anglers all fishing closely together create a fair bit of disturbance , that may spook the Barbel , in effect you have 3 anglers fishing for the same fish , presuming of course that there are any fish there in the first place . All this said fish don't always do what you expect . I was chatting to a couple of Barbel anglers the other day who were sharing a swim , obviously good pals and good anglers , they were fishing within 5 yards of each other and were hooking fish after fish , they were enjoying tremendous sport and having a good old natter as well , great to see . I am no match angler but on occasion I fish short duration summer club matches usually no more than 15 anglers , at the weigh in if the river is low usually only 2 or 3 anglers will have caught a Barbel , most are on the tip using baits that will catch Barbel , usually its the Bream that make up the winning weight , stick 3 anglers on the same stretch in similar conditions and more Barbel will be caught , I think the greater number of anglers , causes more disturbance and less Barbel are caught as a result . Anyway it matters not , you can't beat a good natter when your fishing , after all its not all about catching fish is it !