My proposed system:
Each player has a "Points" and "Games" value that both are initially 0.
When a game with 3 or more players ends with a winner, each player who submitted an entry has their Games increased by 1, and the winner also has their Points increased by the number of submissions in that game. A player's rating is then
floor(1000 * Points / (Games+5)), and the leaderboard is ranked by rating rather than raw wins. (The +5 is to keep new players with early wins from topping the leaderboard prematurely.)
My proposed system: Each player has a "Points" and "Games" value that both are initially 0. When a game with 3 or more players ends with a winner, each player who submitted an entry has their Games increased by 1, and the winner also has their Points increased by the number of submissions in that game. A player's rating is then floor(1000 * Points / (Games+5)), and the leaderboard is ranked by rating rather than raw wins. (The +5 is to keep new players with early wins from topping the leaderboard prematurely.)