All great responses, but Fezzik has the answer that I would look for, as even most wiseguys don't even get the very best number always, but rather know where the value starts and stops, thus know whether to hit or pass.
And as he points out, they always plan on paying six-figured income taxes every year..even if lowballing Uncle Sammie.
Come now Ken, following BW, BB, & HH leaves a bunch of room for error the vast majority of the time..ex:Minn +3..89-71 outright!
P.S. Lurker & Judge Wapner, you two need to post more often, enjoy your wisdom & knowledge.