# How does a preflop solve work?

I recently came across a Peter Clarke video where he was going through a preflop solve in Simpe Preflop. This kind of made me wonder how solving for preflop spots differs from letting the solver run a spot postflop actually.

I have a pretty good grasp of how the solver reaches an equilibrium solution once we input ranges and a specific board. I guess my central question would be whether solving for preflop ranges can be separated from postflop game trees and boards and I guess the answer is no, right? If there would be no postflop action considered, how could the algorithm derive that 4-bet bluffing small suited Aces with straight potential (A5s, A4s) is higher EV than 4-bet bluffing sth like A7s when A5s/A4s never can actually make a straight since no boards are considered?

So I guess it's something like: A preflop solve is the same as a postflop solve just that there are no fixed input ranges. Solver starts finding equilibrium play by randomizing actions over all 1,326 hand combinations pre and postflop, and hence learns that AA just performs better postflop than 72o, performs best in the 3-bet line etc. etc. Should take considerably longer time to solve then.

So does the quality of a preflop solve in essence depend on the number of boards and the width of the postflop game tree that we consider?