I started my fly fishing in St. Louis and bought my first tying stuff at Feather-Craft (and have been a customer ever since, through four moves to different states). I had the good fortune to have Ed and Bob Story teach me to tie the Crackleback as one of my first flies. I now tie it in over a half dozen body colors (usually using turkey rounds as the body), with and without beads, from sizes 8 to 18. I still use their recommended Dai-Riki 300 hook (a 1XL dry fly hook) for both bead and non-bead versions. It's an easy fly to teach and learn, and very versatile in how it can be fished and in how many different species it attracts. It's the prototypical simple attractor fly and is often used around here in one fly competitions. And it doesn't matter to me how you classify it -- it still catches lots of fish!