His argument is that the rich people gambling do not have to pack a lot of odds as in parlay bet to accumulate a high odd size that will give a satisfying potential win. The rich has the money to risk huge amount to a single game for instance 2 odds staked with $1 million to win $2 millions, but the poor staking with $100 to win $2 million has to pick multiple legs to accumulate odds to get such potential win. It hence decreases the gambling winning chance whilst the rich gambler chance remains increased.
Normally the rich gambler can go extra mile in gambling, but that doesn't mean that they can easily get a win with their huge bets. Is still remains what it is, because winning can only happens when the luck is on your side so since is game that luck plays a significant role in determining the final outcome there is nothing like being poor or rich in gambling because sometimes a poor gambler can use a small amount and win a very huge amount that a gambler that calls himself a rich gambler can never win with his huge amount of money. So is not something that you can predict the final outcome correctly.