Checkers

1
Checkers

• Shirley Gates
• Shelley Yamada
• EE496

2
Objective

• Program a checkers game in C
• Rules and strategy of the game
• Design a competent computer player
• Computer player should be efficient
• Time
• Memory

3
Basic Rules of Checkers

• American Checkers Federation (ACF)
• 8x8 board with alternating color squares
• Played on darker color squares
• Each player begins with 12 pieces

4
Moves Jumps

• A regular piece moves diagonally forward
• It becomes a king when it reaches the last row
• A king may move forward or backward
• A piece captures an opponent by jumping
• Jumps must be taken if possible
• Multiple jumps count as a single move
• If a player cannot move , he or she loses

5
Program Design

• Analysis of every possible combination of moves
  is inefficient
• Searching a tree can be made more efficient by
• Recognizing jumps
• Priority, must be taken
• If there are no jump, list all possible moves
• Analyze narrower branches

6
The Board

• 10x10 Array
• With a border
• N Null
• Moves are made in blank squares

7
The Pieces

• Regular Pieces
• Forward left
• Forward right
• Jump forward left
• Jump forward right

• Kings
• Regular piece moves
• Backward left
• Backward right
• Jump back left
• Jump back right

8
Types of Moves

• Choice move
• no jumps, just a single diagonal move
• Choice jump
• there are multiple jumps to chose from, but the
  player is still required to jump
• Forced jump
• a player has no choice but to jump a specific
  piece to a specific square
• Forced move
• a player is cornered into moving a specific piece
  a single space

9
Forced vs Choice

• Control
• Forcing the opponent to move corresponds to your
  control of the game
• Search Tree
• Choice of path
• A single path that is forced and results in gain
  is preferred.
• A narrow tree that also results in gain is also
  good.
• Limits the size of your tree and simplifies your
  required memory
• Strategies
• follow the forced path until it branches and then
  continue for a minimum of 2 or 3 levels

10
Value of Moves

• Another key point to consider is the value of
  your move.
• Capture an opponents piece seems like a good
  move.
• To be captured seems bad.
• However, a sacrifice may be necessary to set up
  your opponent.
• Getting a king is another key in the game.
• It is often said that the first player to get a
  king wins the game.
• This is not always true.
• The king is a versatile and powerful piece
• It can control the game.
• It has more maneuverability.
• It is possible to get a king at the end of a
  series of moves or jumps.

11
Example of Values

• An example of values might be as follows
• capture an opponents piece (1)
• be captured (-1)
• become a king (2)
• opponent becomes king (-2)
• eat an opponents king (3)
• king becomes eaten (-3)

12
Summary

• Rules
• Strategy
• Control
• Program Design
• Analysis of Tree
• Board and Pieces
• Moves
• Types
• Values

13
Conclusion

• Analyzing the different combination of moves and
  their weighted value is important in
  understanding the game of checkers and to
  successfully program a competent human versus
  computer strategy game.
• While designing the interface of the game itself
  is not so difficult, designing an efficient way
  to build and search such a massive tree requires
  a lot more analysis.