My normal approach is not useless here
One of the most famous xkcd panels sweetly lamented the ineffable nature of love thus:
But Ken Van Haren‘s relationship decision-making aid found the correct formula after all. If you’re wondering whether to propose to your partner or ditch them and keep looking, his statistical tool (in beta) can help you figure it out. Once you provide the model with the quality and lengths of your past and current relationships, it will churn out the estimated probability of finding someone better by the date you set. You can argue with the choice of model, of course — he assumes, for example, that the chances of meeting someone tomorrow are not affected by how long you’ve been single — and ultimately, you have to rate your current and past partners on a single number scale from 1.0 to 10.0, which arguably is the hardest part anyway. But hey, it’s something. A more sound way of using probability for help with life choices than tea leaves or tarot.
Plus, I like that it told me I made the right decision five and a half years ago now.