[Transference]

Reasons to Raise a whiffed flop with A high HU
1) There is a strong chance you have the best hand.
2) Theres is a good chance you can fold a better hand.
3) metagame

The value of 2 and 3 almost never surpass 1. With no reads at all you can just about discount them altogether.

One of course is a difficult dillemma, there are things that support the assumption we look for:
A) The board looks like it missed a pre flop raisor.
B) There are 1 or more likely draws on the board.
C) The board doesnt fit the call range of most defenders well.
D) Villian is an agressive defender.

Obviously we can't accurately weight what all these tell us since they are all continuous variables (not either or propositions).

Finally there are barriers to keep in mind when determining if our chance to be ahead is strong
a. Remember, it this spot its 5sb to you, we can immediately give up our share to that for no further cost.
b. When villian leads into us he is folding to our raise on most boards very rarely. In order to force a fold or an incorrect peel we must typically continue on the turn. We have by raising committed to putting another 4 sb into this small pot.
c. We should consider how many outs we have to improve to the best hand when we are behind and how many he has to improve when he is behind. With a hand like A7 you are often drawing slimmer than villian is when either is behind.

The point of all that?
Reflexively playing A high aggressively against unknowns who play back at you is trouble.

A big reason why blind steals and defense are so difficult is because there is an increased likilood that your A high or medicore hand is profitable to show down and an increased liklihood that a worse hand will play back at you. Using a few of these factors is often adequate in most spots, but when HU you must expand your considerations to keep ahead. Any missing information (i.e. reads) is a substantial barrier to overcome.

This is obviously just a short version of a decision tree, there are other possible lines and more considerations. If anyone wants to add to this or comment Id be gratefull.