Is the game skill-based? How can you influence which chestnut breaks? Is the challenge chestnut selection? Or a specific swing method?
I assume the conkers are provided by the organizers, and the participants must select their conker from the collection or given one at random. Prevents tampering I guess.
Going around the conker trees in your area and finding the perfect conker is a huge part of the game. There is also a certain amount of pre-game 'modification' that are generally allowed, like soaking them in various solutions, or baking them in an oven.
Having to use a provided conker would be like showing up to the Tour de France and being assigned a bike by the organisers.