Does anyone skip or alternate fly sizes? For example, instead of carrying Adamses in 14, 16, 18, and 20 just carrying them in 14 and 18 or 16 and 20. I try to carry a minimal amount of stuff on stream and paring down the number of sizes would really help — unless, of course, it ends up not being advantageous.
I mostly fish hatch-matching spring creeks and tail waters. Since I believe size is the most important aspect of any fly, I carry them in all the appropriate sizes for the “bug.” That usually only involves two or three sizes anyway. PMD’s/sulpher’s are 16-20. Same with Baetis. Drakes are 12 and 14. Caddis are 16 and 18. Mahoganys and March Browns are 14 and 16. Midges are 18 and 20, and I even carry/fish a few 22’s. Golden stones and Yellow Sallies are 10-14. Etc. etc. I subscribe to the 1-size, 2-shape, 3-color theory of order of importance in choosing a fly. Often a match of one certain size makes a big difference for me. I can think of many times that a #16 something-or-other would have been too big, and a #20 too small, for the best match. Flies weigh nothing, and a few light boxes can carry way more than anyone ever really needs, so why not have the right size for the hatch presented?