It will be an intriguing but challenging problem to find the "best" partner if you want to get married. If you are not, you can replace this with finding the "best" house, employee, product, etc. Why so challenging?
To make it simpler, let's say if you will be dating 10 people in your life, and you start with the first person, you do not know how well-mached the first people is for you since you have no experience of dating with people. On the other hand, if you already date with 10th people and are about breaking up the relationship since you already knew the 'best' partner was actually 4th girl/boy friend.
Statistics could potentially help us to make our decision easier. This problem has been very popular as "Secretary problem" since 1950. You will need to see first 37% of the number of the people you could potentially date with, and then after that, whenever you find the "best" partner candidates compared to the past candidates, the person would be more likely the "best" partner overall. You can find more detail and the variation of this problem and their solutions from "Algorithm to live by" written by Brian Christian.
Retrospectively I followed this logic for getting married with my wife and I have been very comfortable for my decision so far.