Tired of the "3 dates" fallacy as a hard and fast rule. I have slowplayed top shelf women many times over the years, and the results are better up to as far as two months in before sex.
The trick is that you already have at least 1-2 fairly regular women and let the new one know it very indirectly OR high interest level after a date you aced. If she is hot after you to the point of hinting at sex or a BJ in the car herself on the first two dates, OR if she is blowing up your phone with crumbs from you in between dates OR is asking you out on dates or to come over, OR she is a solid 9+, it is better IME to make her wait a bit. It drives them crazy when you slowplay them and let them chase you for awhile, makes things MUCH easier for you with one you may be interested in past fast sex. Sets you way apart from the thirsty. Of course don't bother with this unless she is extremely good looking and she could be a strong main girl candidate on paper.