We had a simultaneous Kelly Criterion thread awhile ago. It dealt with two independent wagers. Here's a link to that thread:
https://forumserver.twoplustwo.com/2...-math-1644034/
Your case deals with dependent wagers (events), but I imagine that the same approach applies. Mathematically, the Kelly criterion prescribes that a bettor bet amounts on the two wagers that maximizes the expected logarithm of the bettor's ending bankroll.