Your discussion is, as usual, thorough and technically sound, but, if Humpwalker is really a beginner, it might have been more complex than he needs at this time.
I’m not a naval architect, or sailmaker, or physics professor, and I don’t think Humpwalker expected me to be otherwise. I’m a retired lawyer and weekend sailor who has, for many years, had consistent racing success wherever I have raced, and who enjoys sharing what I know with new sailors. Like most people, I am impressed by the depth of your understanding of sailing technology, and grateful for the generous contribution of your time to the forum, but your comments on my post are grossly unfair, plainly wrong and mean-spirited, and I really don’t understand what prompted them.
You begin with the assertion that “ …you are way too obsessed with the slot.” How do you know the amount of importance that I attribute to the slot? Are you saying that adjusting the slot is unimportant? The only clue that I gave to my assessment of the relative importance of the slot is when I said that, in light air it is more important to adjust the slot than it is to tweak the shape of the mainsail in the manner that Humpwalker suggested. I said, get the slot right first, then tweak the mainsail. Do you disagree? Should Humpwalker allow the mainsail to luff while he is fooling around trying to shape it?
Next, you claim that I “…don''t understand the concept of powering up or down a sail plan, and really don''t seem to understand the role of the traveler in powering up or down the sail plan.” Later it becomes apparent that you are really quibbling with my use of the term “depowering.” If you will re-read my post you will see that I never used that term. What I said was “When the windspeed increases, and the boat becomes overpowered, you can narrow the slot and reduce the amount of power that is generated by the sails by easing the traveler to leeward.” Either your sails are “harnessed” to the wind and generating power, or they are “disconnected” from the wind, and flapping uselessly. Do you disagree with my conclusion that easing the traveler to leeward reduces the amount of “power that is generated by the sails?” Is it your opinion that the sails generate more power when you ease the traveler to leeward of the optimum position, in strong winds?
You close by saying that you “…really disagree with the idea that ‘if your sails are basically trimmed correctly, and you are making the kind of fine adjustments that a skilled racer would use, those fine adjustments can''t be measured by your knotmeter.’" My opinion was expressed within the context of the situation presented by Humpwalker. He was trying to slightly tweak the shape of the mainsail in light air. You cannot expect such a minor tweak to register reliably on a knotmeter in light air conditions. I agree that tweaking the mainsail and jib in a variety of ways can, cumulatively, make a significant, observable difference in boat speed, especially in stronger winds, but that was not what Humpwalker was talking about. He was talking about making one little tweak, and then looking at the knotmeter to see if it registered a change in speed. The readings of a knotmeter can be helpful, but are also imprecise and ambiguous. It’s often difficult to determine whether a change in boatspeed is due to a change in sail trim, or to a change in windspeed, or to wave action, or to some other factor. However, there is no ambiguity when the bearing to your opponent changes.