Simple question

[Brion Toss]

Hello,
I'll add that a taper works because compression loads "accumulate" on the way down; there's little inclination for the mast to flex up at the top, where the loads are just starting.
The highest inclinations to deflect are typically seen about a third of the way between the deck and the lower spreaders. So it is also possible to taper the lower part of the mast, and you can see just that in some older vessels, whose wooden masts might be tapered rather radically belowdecks. This could be especially valuable on a ketch, and rather than explain why, I think I'll make it next month's Puzzler.
Fair leads,
Brion Toss