Alan, Jason, and Shervin are playing a game with MafsCounts questions. They each start with $2$ tokens. In each round, they are given the same MafsCounts question. The first person to solve the MafsCounts question wins the round and steals one token from each of the other players in the game. They all have the same probability of winning any given round. If a player runs out of tokens, they are removed from the game. The last player remaining wins the game.

If Alan wins the first round but does not win the second round, what is the probability that he wins the game?

[i]2020 CCA Math Bonanza Individual Round #4[/i]
1. **Initial Setup:**
   - Alan, Jason, and Shervin each start with 2 tokens.
   - Alan wins the first round, so he gains 1 token from Jason and 1 token from Shervin.
   - After the first round, the token distribution is:
     - Alan: \(2 + 2 = 4\) tokens
     - Jason: \(2 - 1 = 1\) token
     - Shervin: \(2 - 1 = 1\) token

2. **Second Round:**
   - Alan does not win the second round. WLOG, assume Jason wins the second round.
   - Jason gains 1 token from Alan and 1 token from Shervin.
   - After the second round, the token distribution is:
     - Alan: \(4 - 1 = 3\) tokens
     - Jason: \(1 + 2 = 3\) tokens
     - Shervin: \(1 - 1 = 0\) tokens (Shervin is eliminated)

3. **Remaining Game:**
   - Now, only Alan and Jason are left, each with 3 tokens.
   - The game continues until one player runs out of tokens.
   - Since both players have the same number of tokens and the same probability of winning each round, the game is symmetric.

4. **Probability Calculation:**
   - The probability that Alan wins the game is the same as the probability that Jason wins the game due to symmetry.
   - Since there are only two players left and they have equal chances, the probability that Alan wins the game is \(\frac{1}{2}\).

The final answer is \(\boxed{\frac{1}{2}}\).