I agree, generally speaking, with the several generation line establishment, depending on how many lines are involved. However, I've seen people take two or three mediocre lines (with very rare stock) and produce birds superior to their predecessors. I think the junior breeder in those instances deserves some credit. But I do think that he should still offer to credit the lines he's using for the first three generations or so out of respect. People can take that politeness with a grain of salt if the junior breeder is the one with the real talent.