Rather than simulate the whole game, it would be simpler to simulate certain key choices. I was thinking there would be a dialogue option stage, then an intelligence check and a die roll to determine if they won or not. For example:
Play a game? Yes / No
(The following are a random array of dialogue choices, which would be different every time.)
1. I play the Queen's Gambit! (50% change to lead to win)
2. I play the King's Pawn opening (50% change to lead to win)
3. I play the Rook Pawn Bluff. (20% change to lead to win)
4. I play the Knight's opening. (40% change to lead to win)
Then there would be a final array of dialogue choices:
1. Play for a small advantage.
2. Play for the draw.
3. Gamble it all for the win.
4. Play to lose.
Then the intelligence check would modify the final die roll and win lose conditions are announced.