In a previous paper, we considered several models of the parlor game baccara chemin de fer, including Model B2 (a $2\times2^{484}$ matrix game) and Model B3 (a $2^5\times2^{484}$ matrix game), both of which depend on a positive-integer parameter $d$, the number of decks. The key to solving the game under Model B2 was what we called Foster's algorithm, which applies to additive $2\times2^n$ matrix games. Here "additive" means that the payoffs are additive in the $n$ binary choices that comprise a player II pure strategy. In the present paper, we consider analogous models of the casino game baccara chemin de fer that take into account the $100\,\alpha$ percent commission on Banker (player II) wins, where $0\le\alpha\le1/10$. Thus, the game now depends not just on the discrete parameter $d$ but also on a continuous parameter $\alpha$. Moreover, the game is no longer zero sum. To find all Nash equilibria under Model B2, we generalize Foster's algorithm to additive $2\times2^n$ bimatrix games. We find that, with rare exceptions, the Nash equilibrium is unique. We also obtain a Nash equilibrium under Model B3, based on Model B2 results, but here we are unable to prove uniqueness.
翻译:在先前一篇论文中,我们研究了赌场游戏“百家乐铁路牌戏”的若干模型,包括模型B2(一个$2\times2^{484}$矩阵博弈)和模型B3(一个$2^5\times2^{484}$矩阵博弈),两者均依赖于正整数参数$d$(牌副数)。求解模型B2下的博弈关键在于我们称之为Foster算法的方法,它适用于可加性$2\times2^n$矩阵博弈。其中“可加性”指收益在构成玩家II纯策略的$n$个二元选择中具有可加性。本文中,我们考虑赌场游戏“百家乐铁路牌戏”的类似模型,加入对庄家(玩家II)胜局征收$100\,\alpha\%$的佣金,其中$0\le\alpha\le1/10$。因此,该博弈现在不仅依赖于离散参数$d$,还依赖于连续参数$\alpha$。此外,该博弈不再是零和博弈。为求解模型B2下的所有纳什均衡,我们将Foster算法推广至可加性$2\times2^n$双矩阵博弈。我们发现,除少数例外情况,纳什均衡是唯一的。我们还基于模型B2的结果获得了模型B3下的一个纳什均衡,但在此无法证明其唯一性。