I see Paul’s point but if you compare all boats using the same criteria (rig measurement) wouldn’t that be the best for comparison. You can’t compare actual sailing as each individual would/could use different sails for the same conditions depending on what sails they have, can afford and sailing experience thus creating differences even when comparing the same boat. Maybe I’m wrong but I would think comparing the same data for each boat (rig measurement) would be the best for getting a good base comparison of what could be vastly different boats. In my case not too different but there are a couple that are designed to be a little faster under sail and the rig measurement also shows that.