Fly tying the 20 incher. This pattern works well in a number of circumstances. It's big, it's buggy, shimmers, wiggles and gets down fast. Fish it in moving water under a strike indicator or a large dry fly, where it can look like a large stonefly nymph, stupidly large mayfly, and also does a good job when there are very large cased caddis larva. I've fished this in a situation where there were both stoneflies and large cased caddis larva, and it exceeded it's name of 20 incher...
