Re: Why is beam reach (or near to it) the fastest point of sail?
No, this isn't related to relative wind. It's related to keel efficiency. A less efficient keel will reach maximum hull speed on a slight broad reach rather than a beam reach (because there is a bit less load on the keel).
Thanks for responding. It seems that everyone else is intent on beating each other senseless with the points they score. Thanks also to those who pointed out that in my iPhone brainlessness, I switched forward and backwards. As you say, the apparent wind moves forward as you travel faster.
However, still interested in whether polars would tell you anything more if based on apparent rather than true wind. It would make it easier to conceptualize what the masthead is telling me.