2. There are 9 boxes arranged in a row on the table, and next to them is a bucket with an ample supply of small balls. Jia and Yi play a game: Jia and Yi take turns, with Jia going first. Jia can take 25 balls each time and distribute them into any of the boxes, while Yi can empty all the balls from any two consecutive boxes back into the bucket and return the boxes to their original positions. Jia can end the game at any time and point to one of the boxes, with the number of balls in that box being Jia's score, while Yi tries to prevent Jia from scoring high. Question: What is the maximum score Jia can achieve?
【Analysis】We refer to the state before Player A acts as the beginning of a round, and one round is completed after both Player A and Player B have acted. We first describe Player A's strategy to achieve 75 points.

Player A only places balls in boxes 1, 3, 5, 7, and 9. For Player B, the optimal strategy is always to take the box with the most balls. Player A starts by placing balls as evenly as possible in these boxes, ensuring that the difference in the number of balls in each box does not exceed 1. If Player B takes no more than 24 balls from one box, Player A will replace the same number of balls and distribute the others evenly. After one round, if the initial number of balls is \( y \leq 95 \), the total number of balls will increase by \( 25 - \left\lceil \frac{y + 25}{5} \right\rceil \geq 1 \) per round. Therefore, Player A can repeat this step until the total number of balls in all five boxes reaches 121, i.e., the five boxes will have 25, 24, 24, 24, and 24 balls respectively. (6 points)

Next, Player B will obviously take the box with 25 balls. In the following rounds:
1: Player A places 6 balls in each of the remaining 4 boxes, and Player B takes one box, leaving 30 balls in the remaining three boxes.
2: Player A places 8 balls in each of the remaining 3 boxes, and Player B takes one box, leaving 38 balls in the remaining two boxes.
3: Player A places 12 balls in each of the remaining 2 boxes, and Player B takes one box, leaving 50 balls in the remaining one box.
At this point, Player A places 25 more balls, bringing the total in this box to 75 balls. (9 points)

Next, we describe Player B's strategy to ensure that Player A cannot achieve 76 points. Divide the boxes into five groups: 12, 34, 56, 78, and 9. When no box has more than 25 balls, Player B takes the group with the most total balls. (12 points)

When a box has at least 25 balls, Player B takes the group containing the box with the most balls. (15 points)
Under this strategy, if Player B performs the second operation, the total number of balls does not increase. When performing the first operation, if the initial number of balls is \( y \), the number of balls after one round is at most \( y + 25 - \left\lceil \frac{y + 25}{5} \right\rceil \). This means that Player B can always keep the total number of balls below 121. (18 points) If Player A achieves 76 points in round \( n \), then at the beginning of this round, the box must have at least 51 balls.

In round \( n-1 \), Player B must have taken a box with at least 51 balls, so the total number of balls in these two boxes at the beginning of the round must be at least 77, and the box with the most balls must have at least 39 balls.

In round \( n-2 \), Player B must have taken a box with at least 39 balls, so the total number of balls in these three boxes at the beginning of the round must be at least 91, and the box with the most balls must have at least 31 balls.

In round \( n-3 \), Player B must have taken a box with at least 31 balls, so the total number of balls at the midpoint of this round must be at least 122, which is a contradiction. (21 points) Therefore, by executing this strategy, Player B can ensure that Player A can never achieve 76 points, indicating that 75 is the maximum score Player A can achieve.

【Comment: 3 points for the answer, 6 points for Player A's strategy, and the description of Player B's strategy is more challenging. If only a simple strategy of taking the group with the most balls is given, 3 points are awarded. 】