Judging by who wears what number during the quidditch match in the film adaptation of Harry Potter and the Half-Blood Prince however, the possible position numbers may be one for keeper, two and three for beaters, four, five, and six for chasers, and seven for the seeker.

Why is Harry Potter's quidditch number 7?

The number on the back of Harry Potter's Quidditch robes in the films is seven (this could be a reference to the fact that usually the best player/captain in a football team, has the number 7 shirt).

What do the quidditch numbers mean?

The number you wear is based on which position you play on the team – 1 for keeper, 2/3 for beater, 4/5/6 for Chaser, or 7 for seeker.