Well i know im fishing for those lunkers but i still have the smaller 10-15" fish hit my #2 and #4. I like them big then have a few different nymphs trailing it so that bigger heavier wire worm will drag them to bottom and they bounce on bottom therefore putting it right in front of the fishs face and there are three floating past them so its like a lil buffet. So my main sizes are #2 and #4 but if your targeting smaller fish i would go with a #6