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Game Theory |
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Calculus MethodThis method is almost similar to the previous method except that instead of equating the two expected values, the expected value for a given player is maximized.
Consider the zero sum two person game given below:
Formulas: The solution of the game is: A plays (p, 1 - p) where:
B plays (q, 1 - q) where:
Value of the game, V = apq + c(1 p)q + bp(1 q) + d(1 p)(1 q) To illustrate this method, consider the same example discussed in the previous section.
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| Player B | |||
|---|---|---|---|
| Player A |
|
I | II |
| I | 2 | -1 | |
| II | -1 | 1 | |
This game has no saddle point.
| p = | 1 - (-1) ----------------------- (2 + 1) - (-1 - 1) |
= |
2
---- 5 |
1 p = 3/5
| q = | 1 - (-1) ----------------------- (2 + 1) - (-1 - 1) |
= |
2
---- 5 |
1 q = 3/5
V = 2 X 2/5 X 2/5 + (-1) X 3/5 X 2/5 + (-1) X 2/5 X 3/5 + 1 X 3/5 X 3/5 = 1/5
Example 2Solve the game whose pay-off matrix is given below:
| Player B | |||
|---|---|---|---|
| Player A |
|
I | II |
| I | 1 | 3 | |
| II | 5 | 2 | |
This game has no saddle point.
| p = | 2 - 5 ----------------------- (1 + 2) - (3 + 5) |
= |
3
---- 5 |
1 p = 2/5
| q = | 2 - 3 ----------------------- (1 + 2) - (3 + 5) |
= |
1
---- 5 |
1 q = 4/5
V = 1 X 3/5 X 1/5 + 5 X 2/5 X 1/5 + 3 X 3/5 X 4/5 + 2 X 2/5 X 4/5 = 13/5