In my opinion, I figure 3 perch to the lb... So a 30 limit at ten lbs would be a good/ very good weight!! At four perch to the lb, I consider that a minimal catch as far as size goes. Back in my younger days, it was easier to get that three fish to the pound.....but..as I am now retired and I clean my own fish, I am far more fussy about size. What I keep now needs to be close to 9" or they go back, total number is less important !! Getting back to my 3 per lb catch rate.