This idea includes gamification and further incentives for people to get involved. It also allows everyone a chance at winning while still allowing the usual winners to win (business as usual).
My proposal is that on top of the normal prize, all players have the chance to win an additional token (whole other second draw). This token will be non-transferrable and winning it will be based on address, (not the number of tickets). I.e. every address has an equal chance of winning it. Secondly, to win anything the user must collect x number of these tokens (let’s say 4). This reduces sybil and prevents farming. A single address must be lucky enough to win this token 4 times (4 different draws where every address has equal odds). Since it’s non-transferable they can’t farm the token. Since they can’t transfer it they can’t increase their odds with extra wallets since they still have to win multiple times per address. The only improved sybil probability is that by having extra wallets you increase your odds of having a wallet that wins 4 times, but I think this at least makes a decent effort to mitigate it.
Owning these 4 tokens will then allow the user to redeem the prize.
If we wanted to go down the NFT path (if they can be made non-transferable), for example the 4 tokens could be the POOL together token logo broken into 4 slices (top-left to bottom-right). The first user to posses all 4 unique pieces and create the whole logo could claim the prize. The slices to be won could cycle over time and it could create a lot of speculation about who will finally be the one to win. It could end up taking a while to actually have a winner.
Although you could just use any old non-transferable ERC20. I like the logo idea because it’s also a good marketing potential for the PT token.
For added security to be eligible you could also require that each address had deposited x amount for x amount of time.