1. Let's first understand the problem: Two teams, X and Y, play football, and the first team to score 3 goals wins the match. 2. The branching structure represents all possible sequences of goals scored by teams X and Y until one team reaches 3 goals. 3. Each node labeled "X" represents a state in the match where the game continues, and branches represent possible next goals scored by either team. 4. We do not grow further branches from nodes where a team has already reached 3 goals because the match ends immediately when a team reaches 3 goals. 5. This is why some branches stop early: they represent terminal states where the winner is decided, so no further goals or branches are possible. 6. In summary, branches are only grown while the match is undecided (no team has 3 goals yet). Once a team reaches 3 goals, the branch ends, reflecting the end of the match. This explains why some branches do not grow further in the tree structure.