As always Charlie's straightforward and experienced, facts only, keep it simple, take....I like it. The hotbed of Colorado is blessed with a myriad of signature tiers....Charlie Craven, Pat Dorsey, Landon Myer, John Barr, Jack Dennis, Rick Takahashi (TAK's), Greg Garcia, Mark Engler (WD40), A.K. Best, among several others, are all among some of the more notable. Charlie is, and has always been, just a good guy that lives to fish. Interestingly, many of these notable tiers are also either guides, or have guided previously - and their patterns were employed in real world scenarios long before they became recognized as a production fly.
He seems to think there are no odd numbered sizes? say that a 1X goes up (or down) two hook sizes?
"The increments in which a hook gap is increased are by hook sizes. For instance, a 1X wide-gap size 14 hook should have a gap equal to that normally found on a size 12 standard hook. A 2X wide-gap size 14 should sport the gap normally found on a size 10 standard hook, and so forth.
To add complexity, also consider the variations in wire sizing. Some hooks are made of wire heavier (X-heavy) or lighter (X-fine) than what would be considered standard, so a size 14 1X-heavy hook is made from wire normally used on a standard size 12 hook, and a 2X-heavy size 14 would be made of wire typically used in a standard size 10 hook. That same size 14 in 1X-fine would be made from wire normally used in a standard size 16."