The typical form of a nearest wins question in SpeedQuizzing is a final question at the end of the night which requires a number for the answer. Whoever is nearest fastest gets an amount of points, that the host can decide upon (the default is 30 points).
Example Question: "How many times is the "F" word used in 'Pulp Fiction'?"
Answer: 265
Fundamentally the employment of a 'nearest wins' question at the end of the quiz only involves the top few teams. They should be used very judiciously, not as a 'Golden Snitch' which effectively negates a great deal of the good play and drives a bulldozer through the previous two hours.
Do they improve numbers? That is the bottom line; do people like them? I don't know. I don't mind them for small amounts, but not 25% of the total value of the quiz. I have been to quizzes which use five of them which have only had five teams playing so… the jury is at least out!
Many a host will look at the scores and decide to place a value to lasso in a particular number of teams, perhaps the majority, or even just so the second team can catch the first. Goalpost moving by a referee is not indicative of a good game. Be consistent.
Nevertheless fast tracks can be fun. And many people love Harry Potter. But J.K. Rowling has said "To be honest with you, Quidditch matches have been the bane of my life"!
I respectfully suggest that if you are going to use them, keep their values down to that of three or so questions, the default value is not, IMHO, far off the mark.