Game Theory Quiz

[Jazza]

This has been posted in the poker theory forum, but it doesn't look like anyone's gonna try it, so i'll post it here for you guys if you wanna give it a try

The game is pot limit 1-card, the deck consists of 5 cards, the A,2,3,4 and 5.

The ace is low, so the 5 is the nuts.

You each ante $100. There are two betting rounds. It is pot limit, so to start off you can be anywhere from $1 to $200 since you both have $100 each in the pot to start.

Now suppose you are playing some one heads up, you are last to act in both betting rounds, and before the first round your opponent decides to have a little fun and flip his card face up, it's the 4.

What's your strategy, and what minimum EV does your strategy guarantee?