"Challenging The Money Pool"
This 1000 silver coins from the administration fee would be divided among the other players and the staff, so each of them would get at least 100 coins whether the challenger won or lost the game.
To win, the challenger had to win 10 consecutive rounds and got all the money from the 10 rounds betting, plus the money from the money pool.
If the challenger won, they would spend literally only 1000 silver coins as the starter fee. They would then get much more than that.
But if they lost, they would lose big time. Because of this, only a few crazy rich people would try the challenge. Even the tower climber or skippers wouldn't dare to do this.
It's too risky!
Who could accurately guess the number slot that the ball would land into for 10 consecutive times?
Unless they could see the future, which was an ultra-rare ability, no ability users would be confident.