I saw this a lot in game development. If your leaderboards are being attacked by 'cheaters', the best solution is to legitimize the cheater gameplay and quarantine them from the other players.
In this case it would involve creating a second leaderboard and letting participants register for either the manual or AI leaderboards.
There will still be trolls, it's not perfect. But the majority of these players simply disagree with your definition of cheating and will happily self-select in return for anointing their playstyle and giving them an arena to square off in with other like-minded players.
Plus you'll get lots of good data, tagged by your users, as to what a cheating score looks like, what IPs they come from, etc. You could use this to prune your other leaderboard if you really cared.
In this case it would involve creating a second leaderboard and letting participants register for either the manual or AI leaderboards.
There will still be trolls, it's not perfect. But the majority of these players simply disagree with your definition of cheating and will happily self-select in return for anointing their playstyle and giving them an arena to square off in with other like-minded players.
Plus you'll get lots of good data, tagged by your users, as to what a cheating score looks like, what IPs they come from, etc. You could use this to prune your other leaderboard if you really cared.