Amante, I was the one who introduced double- and triple booking into the mainstream for men in the context of OLD. It was brought strictly in response in how to deal with OLD women most effectively.
1) You mentioned in another thread that you can identify if a woman will be attractive enough in person by her pics. If you are as OLD seasoned as you say you are, then you know this is certainly not true. Conversely, some of the best women I have met in person did not appear so attractive in their pics. With the photo-editing tools available today, the angles, the lighting, 2d vs 3d, aesthetic injections (scupltra, radiesse, restalyne), skin-tightning tools (Ultherpay, thermage), makeup/artistry among dozens of other stratagems or augmentations, you cannot with 100% certainty know how a woman will look in person based on even an assiduous evaluation of her pics. And this is coming from a guy who is extremely keen on facial/body aesthetics (e.g. See Richard's pics).
For this reason alone, before knowing how a date will appear in person, it's an imprudent investment of time and attention to build deeper rapport before the date.
2)
a. Last year around August, I scheduled five dates, one double- and one triple header for Friday and Saturday night, spread one hour apart.
All five showed and were not to my physical liking. Had I invested time into building rapport with them before the date, I would have injudiciously and unnecessarily doled out my time and attention.
b. Last year, sometime after that, I scheduled four dates, two-double headers spread 30 min apart for Friday and Saturday night. It just so turned that all four were attractive this time. I built a harem of four women in under 24 hours. This was the most resourceful, economic use of my time.