Sam-
You have essentially delineated the main differences- That is the "strictness" or limits of the rules regarding a particular boat or class. And there are even "sublevels" apparently since people refer to "strict one designs" (as opposed to apparently "looser" one-designs).
However the terms ARE useful IMO as a general indication of the "strictness" of the rules regarding a particular boat or class (realizing these DO shange once a class is "established" and may tend to cloud the distinction).
I'm sure you know most of this but allow me to enunciate to try to get others involved in this discussion-
Generally most strict are the "one designs" although great variety can exist here and who determines the rules (class, owners, manufacturer) varies. The Tornado is considered "one design" because all boats must in fact conform to a single "design" originally approved and subsequently slightly modified. Only small differences are allowed and these are generally in place to account for production differences (although some builders/owners try or do use these "discretions" to try to gain an advantage). However exactly WHO makes the various parts of the boat is entirely open as long as they meet the "design" specifications.
Hulls, spars, sails, rigs are generally tightly controlled and either offerred by one maker or like in appearance, etc.
"Formula classes" are an offshoot of the old "Development classes" (which included the "A, B, C, and D" classes which had very minimal rules or limits thereby encouraging development of new rigs, hulls, materials, etc.) in an attempt to allow different manufacturers to build boats that were similar enough to allow them to race together head-to-head (sort of like NASCAR) such that the best prepared boat and best skipper will win, overall. Boats can be optimized for a particular crew to some extent and/or particular conditions which may give them an "edge" under those circumstances (light air flat water vs heavy air and waves for instance) but would result in a consequent disadvantage in others. The true aim of any Formula Class is to have all the boats reasonably close in performance (IMO), although this performance may move "up" in relation to other boats outside the class, the Class as a whole should be relatively "equal". Boats may only superficially resemble each other and will typically be supplied by multiple manufacturers with the Class in control of the rules.
Development classes allow much more experimentation, such that "breakthrough" boats can, and are encouraged, to develop so whoever can come up with (ie "develop") a faster hull shape, better rig, use some new material, etc. should "win"- again these can be optimized for certain conditions (ala the "C class Little America's Cup boats") but there is NO intent for all the boats to be close. In fact an intent of the Classes is for the boats to constantly "develop" into faster boats.
There are very few (any??) true 100% Development "classes" anymore- even the IACC boats have restrictive "rules" in place to limit costs (and look at how much the still manage to spend?!) and try to keep competition somewhat close.
IMO this is what has resulted in the confusion you allude to regarding the distinction between these classes: Many of the "Development" classes have CHOSEN to apply more restrictions (like the "A" cat rule on minimum boat weight) to their class in efforts to encourage more "even" competition between boats, increase competitive lifespans of boats, keep costs reasonable, etc.
Perhaps we should all agree on definitions for the terms "One design", "Formula" and "Developmental", with perhaps subcategories of each to lessen this confusion?
Kirt
