On the optimal strategy in a random game

被引:4
作者
Jonasson, J [1 ]
机构
[1] Chalmers Univ Technol, Dept Math, S-41296 Gothenburg, Sweden
关键词
zero-sum game; saddle point; equalizing strategy;
D O I
10.1214/ECP.v9-1100
中图分类号
O21 [概率论与数理统计]; C8 [统计学];
学科分类号
020208 ; 070103 ; 0714 ;
摘要
Consider a two-person zero-sum game played on a random n x n-matrix where the entries are iid normal random variables. Let Z be the number of rows ins the support of the optimal strategy for player I given the realization of the matrix. (The optimal strategy is a.s. unique and Z a.s. coincides wit the number of columns of the support of the optimal strategy for player II.) Faris an Maier [4] make simulations that suggest that as n gets large Z has a distribution close to binomial with parameters n and 1/2 and prove that P(Z = n) less than or equal to 2(-(k-1)). In this paper a few more theoretically rigorous steps are taken towards the limiting distribution of Z: It is shown that there exists a < 1/2 (indeed a < 0.4) such that P((1/2 - a) n < Z < (1/2 + a)n) --> 1 as n --> infinity. It is also shown that EZ = (1/2 + o(1))n. We also prove that the value of the game with probability 1 - o(1) is at most C-n(-1/2) for some C < infinity independent of n. The proof suggests that an upper bound is in fact given by f(n)n(-1), where f(n) is any sequence such that f(n) --> infinity, and it is pointed out that if this is true, then the variance of Z is o(n(2)) so that any a > 0 will do in the bound on Z above.
引用
收藏
页码:132 / 139
页数:8
相关论文
共 7 条
[1]   On the existence of maximum likelihood Nash equilibria [J].
Balder, EJ .
ANNALS OF OPERATIONS RESEARCH, 2002, 114 (1-4) :57-70
[2]   Cooperation and self-interest: Pareto-inefficiency of Nash equilibria in finite random games [J].
Cohen, JE .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1998, 95 (17) :9724-9731
[3]   PROBABILITY THAT A RANDOM GAME IS UNFAIR [J].
COVER, TM .
ANNALS OF MATHEMATICAL STATISTICS, 1966, 37 (06) :1796-&
[4]  
Faris W. G., 1987, Complex Systems, V1, P235
[5]  
Owen G., 2001, GAME THEORY
[6]   On the number of pure strategy Nash equilibria in random games [J].
Rinott, Y ;
Scarsini, M .
GAMES AND ECONOMIC BEHAVIOR, 2000, 33 (02) :274-293
[7]   A NOTE ON THE PROBABILITY OF K-PURE NASH EQUILIBRIA IN MATRIX GAMES [J].
STANFORD, W .
GAMES AND ECONOMIC BEHAVIOR, 1995, 9 (02) :238-246