I would make the following changes: - Make the candidates be the main event, the winner is WC. - score games as in soccer, 3 points for a win, 1 for draw, 0 for lose.

These changes increase the stakes, incentivize offensive chess, allow the sitting WC to play all the best players rather than one, reduces the time commitment to a single event for the challengers, and allows the WC to partake in the most prestigious tournament.