Do you think this is possible? If so, what is the astrology?
I think the outcome of many relationships can be predicted, contingent on the free will of the people involved.
I know that's not very defined. I'll just say, I do this all the time. Tell clients when a relationship is hard wired vs opt in or out. When they may last vs will last vs, "give it a month". 
@elsa that makes sense!
I should have specified—when a relationship will begin—does anyone believe it can be detected in your own chart, SR, progression, or ?
@belladonna Yes, I think you can often see this as well... serious relationship, in particular. It's really is, when a person is ready, a viable person comes on stage.
I've definitely noticed that the sign on the cusp of the 7th house is very often the sign of the natives first love or first spouse. Natal charts with heavy 7th house placements tend to get lots of options for dating, while empty 7th houses have fewer. Long term transits like Jupiter, Neptune, North Node or even Saturn to the 7th house tend to bring opportunities for partnering up.
In a similar way, the 8th house brings opportunities for relationships, but the motives tend to be different from the 7th.
@draco Yes, this is true for me. My first and second loves were Virgos (my 7th house sign). My partner also has many planets in Virgo.