connect to metamask
Its really up to you. In practice, I usually upfront tell people that I'll reward someone a first place reward and reward a second or third place.
If you haven't done that upfront, then I guess you could decide whether you want to split the reward or you want to just pay 100% to the first place person.
I don't like to burn bridges, so I usually pay out people who put in some level of effort a least a little.