DNL, Act7
Represent strategy games evolution with a tree
1. X plays first. Who do you think would win in this game?
2. Represent the different evolu ons of the game using a tree.
3. For each terminal node of the tree, indicate the winner.
Use a color code: Blue for X , Red for O, Black for a draw.
4. How many possible games are there?
5.
a. How many wins for X?
b. How many wins for O?
c. How many draws?
6. Assuming a random play strategy, what is the probability of:
a. An X-win?
b. An O-win?
c. A draw?
In Ac vity 4, we observed that Go is harder than chess due to its larger branching factor.
The branching factor is the average number of moves available to a player at each turn.
7. Why is it called a branching factor? (Hint: branches are part of trees).
The maximum number of moves on a Go board is 19×19=361.
In chess, the typical number of legal moves is around 30.
8. We assume a chess game where each player has a constant 30 moves per turn.
a. How many possible games are there a er two rounds (for both players)?
b. How many possible games are there a er four rounds (for both players)?
9. We assume a Go game where each player has a constant 300 moves per turn.
a. How many possible games are there a er two rounds (for both players)?
b. How many possible games are there a er four rounds (for both players)?
10. Why do you think the branching factor is important to determine the difficulty of the game.