As others have said, it is going to depend on the field and the program. I can only speak about my field, which is relatively small. The dinners matter, a lot. We match people that gel with our current residents. We have plenty of superstars numbers applicants. We have plenty of superstar research applicants. We could blindly pick out of a hat and we would get someone who was good on paper. But, just as important, we have to be around you for 6 years. We have to train you. You have to train your juniors. You have to work with 80+ hours/week our current residents. If you don't fit, it is a waste of everyone's time. The dinners are an opportunity to meet us. We have a lot of diversity in our residency. Lots of different backgrounds, lots of different interests. Some people drink (a lot), some (yours truly) don't drink at all and everyone else is somewhere in between. The same goes for virtually every metric. What you won't find are a bunch of dinguses. But, what you will find are a bunch of people that get along well.
We believe in volume of information. The dinner and the interview day are long, there is a lot of group and one on one interaction. And every year, we can right off the bat not rank people based on those interactions.
Probably 1 in 8-10 are enough outside of 'normal' in a bad way as far as we are concerned.