Single Big Bet - Highest Winning %.

[RocketManJames]

A friend is going to Vegas. He wants to put down a single big bet ($250) if he is ahead at least that much by the end of his trip. He KNOWS this is a -EV play, but frankly, he thinks it would be exciting.

What is the best game to place this single big bet. He would be equally happy to win $250 as he would $375. So, he probably would not want to play BJ. EV-wise, BJ might be better than other games, but the extra EV gained is from getting blackjack or doubling down at opportune times. He wants to win at least even money with the highest percentage of time. Assume, for example, that he would prefer a negative EV game that would get him even money 51% of the time vs. a +EV game that would get him $1000 35% and $500 10% and lose 55%.

What game has the highest "at least even money" win percentage?

Please, no comments on the stupidity of making such a bet... it's his money after all.

Thanks everyone,
RMJ