Charlotte is an extremely attractive woman in her late 30s. She is college educated, compassionate, sporty (good skier) and her beautiful craftwork could make Martha Stewart envious. No kidding. It would be easy to write her ad without any exaggeration. She has never had a want of suitors since the age of 13, when I first met her. – Still, she has been just as extremely unlucky in love. After several broken relationships, she is just about to give up on the couple thing. One thing that did puzzle me was her choice of partners: while honest and friendly, they were quite average in about everything else including looks, education, interests and effort.

Charlotte, for all I can see, has never held out for somebody in her own league. I would rather place her film star looks, bright mind and exquisite taste next to a hard-working, highly educated overachiever. A category that neither of her former partners inhabited.
This prompts me to plough the literature for 5 facts to keep in mind when choosing your own league:

1.  You need to set your own standard and search for it. If you don’t find the quality you are looking for where you are, (also if you don’t really know how good things can get) you need to cast your net more widely. This means online dating, singles groups and, why not, the classic matchmaker. It also means pursuing your values. Fighting for a cause, whether in politics, an NGO or in your neighborhood community will unearth people who think on your wavelength.
2. Men tend to overestimate, women to underestimate their attractiveness. (And within each gender, more attractive people underestimate, and less attractive ones overestimate their prowess.) Says this research. What is more, men become especially overconfident with attractive women. In the light of this, ladies and gentlemen (and stunners and wallflowers) kindly adjust your earlier assessment of yourself.
3. Your league is relative. It can always be higher than you thought, in the right environment. As several speed dating studies found, your dating opportunities depend largely on circumstance. So choose your circumstances wisely.
4. People in your league tend to like the same things as you. Taste is a good proxy for education, and education and effort are reasonable proxies for achievement. Moreover, it is good to choose a partner that likes the same things as you and enjoys doing them together; this will enhance relationship quality later on says research quoted here.
5. Your confidence signals who you are. Check here. In a world where people don’t know you yet, they will go by the signal you send yourself. If it places a high value on yourself, that is the value people will assume.