Both parties, A and B, are playing a game called "Stick, Tiger, Chicken." Each person has four cards: Stick (A), Tiger (B), Chicken (C), and Worm (D). Each card can only be used once. Both players play their cards simultaneously without seeing the other's card, and a referee announces the result of each round.

Rules:
1. Stick beats Tiger, Tiger eats Chicken, Chicken eats Worm, Worm beats Stick, and so on in a cycle.
2. If both players play the same card or cards that are one step apart in the cycle, it is considered a draw.

Assuming you are one of the players, deduce what cards your opponent played each round based on the cards you played and the results of each round.

Rounds:
Round 1: B, draw.
Round 2: A, draw.
Round 3: D, loss.
Round 4: C, win.

Use a list of letters to show your answer. For example, <<<A,B,C>>>.