桥牌竞技中的概率问题
桥牌是一种概率游戏,其叫牌体系和打牌路线的设计要以概率计算为基础,牌力与控制力的估算标准也要靠概率分析作科学论证,概率常识已经成了牌手们掌握胜
算的诀窍。
1.常见牌型概率:依据概率计算,常见牌型概率如下(R程序):
自己手上的牌型分布计算:
思路:每个花色都有13张,依次抽取。
4-4-3-2 21.55% 4!*(13!*39!/52!)*(13!/4!/9!)*(13!/4!/9!)*(13!/3!/10!)*(13!/2!/11!)/2!
factorial(4)*choose(13,4)*choose(13,4)*choose(13,3)*choose(13,2)*factorial(39)/factorial(52)*factorial(13)/factorial(2)
5-3-3-2 15.52% factorial(4)*choose(13,5)*choose(13,3)*choose(13,3)*choose(13,2)*factorial(39)/factorial(52)*factorial(13)/factorial(2)
5-4-3-1 12.93% factorial(4)*choose(13,5)*choose(13,4)*choose(13,3)*choose(13,1)*factorial(39)/factorial(52)*factorial(13)
5-4-2-2 10.58% factorial(4)*choose(13,5)*choose(13,4)*choose(13,2)*choose(13,2)*factorial(39)/factorial(52)*factorial(13)/factorial(2)
4-3-3-3 10.53% factorial(4)*choose(13,4)*choose(13,3)*choose(13,3)*choose(13,3)*factorial(39)/factorial(52)*factorial(13)/factorial(3)
6-3-2-2 5.64% factorial(4)*choose(13,6)*choose(13,3)*choose(13,2)*choose(13,2)*factorial(39)/factorial(52)*factorial(13)/factorial(2)
6-4-2-1 4.70% factorial(4)*choose(13,6)*choose(13,4)*choose(13,2)*choose(13,1)*factorial(39)/factorial(52)*factorial(13)
6-3-3-1 3.45% factorial(4)*choose(13,6)*choose(13,3)*choose(13,3)*choose(13,1)*factorial(39)/factorial(52)*factorial(13)/factorial(2)
5-5-2-1 3.17% factorial(4)*choose(13,5)*choose(13,5)*choose(13,2)*choose(13,1)*factorial(39)/factorial(52)*factorial(13)/factorial(2)
4-4-4-1 2.99% factorial(4)*choose(13,4)*choose(13,4)*choose(13,4)*choose(13,1)*factorial(39)/factorial(52)*factorial(13)/factorial(3)
7-3-2-1 1.88% factorial(4)*choose(13,7)*choose(13,3)*choose(13,2)*choose(13,1)*factorial(39)/factorial(52)*factorial(13)
6-4-3-0 1.33% factorial(4)*choose(13,6)*choose(13,4)*choose(13,3)*choose(13,0)*factorial(39)/factorial(52)*factorial(13)
5-4-4-0 1.24% factorial(4)*choose(13,5)*choose(13,4)*choose(13,4)*choose(13,0)*factorial(39)/factorial(52)*factorial(13)/factorial(2)
5-5-3-0 0.90% factorial(4)*choose(13,5)*choose(13,5)*choose(13,3)*choose(13,0)*factorial(39)/factorial(52)*factorial(13)/factorial(2)
6-5-1-1 0.71% factorial(4)*choose(13,6)*choose(13,5)*choose(13,1)*choose(13,1)*factorial(39)/factorial(52)*factorial(13)/factorial(2)
6-5-2-0 0.65% factorial(4)*choose(13,6)*choose(13,5)*choose(13,2)*choose(13,0)*factorial(39)/factorial(52)*factorial(13)
7-2-2-2 0.51% factorial(4)*choose(13,7)*choose(13,2)*choose(13,2)*choose(13,2)*factorial(39)/factorial(52)*factorial(13)/factorial(3)
7-4-1-1 0.39% factorial(4)*choose(13,7)*choose(13,4)*choose(13,1)*choose(13,1)*factorial(39)/factorial(52)*factorial(13)/factorial(2)
7-4-2-0 0.36% factorial(4)*choose(13,7)*choose(13,4)*choose(13,2)*choose(13,0)*factorial(39)/factorial(52)*factorial(13)
7-3-3-0 0.27% factorial(4)*choose(13,7)*choose(13,3)*choose(13,3)*choose(13,0)*factorial(39)/factorial(52)*factorial(13)/factorial(2)
8-2-2-1 0.19% factorial(4)*choose(13,8)*choose(13,2)*choose(13,2)*choose(13,1)*factorial(39)/factorial(52)*factorial(13)/factorial(2)
8-3-1-1 0.12% factorial(4)*choose(13,8)*choose(13,3)*choose(13,1)*choose(13,1)*factorial(39)/factorial(52)*factorial(13)/factorial(2)
8-3-2-0 0.11% factorial(4)*choose(13,8)*choose(13,3)*choose(13,2)*choose(13,0)*factorial(39)/factorial(52)*factorial(13)
7-5-1-0 0.11% factorial(4)*choose(13,7)*choose(13,5)*choose(13,1)*choose(13,0)*factorial(39)/factorial(52)*factorial(13)
6-6-1-0 0.07% factorial(4)*choose(13,6)*choose(13,6)*choose(13,1)*choose(13,0)*factorial(39)/factorial(52)*factorial(13)/factorial(2)
8-4-1-0 0.05% factorial(4)*choose(13,8)*choose(13,4)*choose(13,1)*choose(13,0)*factorial(39)/factorial(52)*factorial(13)
9-2-1-1 0.02% factorial(4)*choose(13,9)*choose(13,2)*choose(13,1)*choose(13,1)*factorial(39)/factorial(52)*factorial(13)/factorial(2)
7-6-0-0 0.01% factorial(4)*choose(13,7)*choose(13,6)*choose(13,0)*choose(13,0)*factorial(39)/factorial(52)*factorial(13)
9-2-2-0 0.01% factorial(4)*choose(13,9)*choose(13,2)*choose(13,2)*choose(13,0)*factorial(39)/factorial(52)*factorial(13)/factorial(2)
其它 0.01%
某一个花色的分布计算:
4-4-3-2 21.55% factorial(4)*choose(13,4)*choose(9,4)*choose(5,3)*factorial(39)/factorial(52)*(13*12*11*10)^2*(13*12)^2*11/factorial(2)
思路:四个方位全排列,由于4重复,需要除以2!,某花色13张牌,先抽4张放一方,再抽4张,抽3张,剩下2张。每一方最多13张牌,因此依次13*12*11...
殊途同归,结果是一样的。
2.防守方牌张分配概率:依据机会均等原则,防守方在某一门花色上的牌张分配似乎总是理当趋近于均匀,但桥牌分牌竟必不同于扔硬币,概率测算结果自然会有
些异常:牌张数=奇数(3,5,7)时,均匀分配(2-1,3-2,4-3)概率均大于50%,对庄家有利。牌张数=偶数(4,6,8)时,平均分配概率均小于50%,非均匀分配(3-1,4-
2,5-3)概率反而更大,对庄家不利。唯牌张数=2例外,1-1分配概率52%,2-0分配概率48%。依据概率公式计算的防守方牌张分配概率列表如下:
外面2张,1-1分布的概率52% 13/25(条件概率,第一张先选定,第二张在同一牌手手上只有12个位置供选择)
外面2张,2-0分布的概率48% 2*13/26*12/25
外面3张,2-1分布的概率是78% 2*choose(3,1)*13/26*12/25*13/24
外面3张,3-0分布的概率是22% 2*13/26*12/25*11/24
外面4张,2-2分布的概率只有40.7%,choose(4,2)*13/26*12/25*13/24*12/23将牌只有AK想要一墩不丢最好的路线是打3-1分布并考虑飞牌。
外面4张,3-1分布的概率是49.74% 2*choose(4,1)*13/26*12/25*11/24*13/23
外面4张,4-0分布的概率是9.57% 2*13/26*12/25*11/24*10/23
外面5张,3-2均匀分布的慨率有67.83% 2*choose(5,3)*13/26*12/25*11/24*13/23*12/22
外面6张,3-3分布的概率35.53% choose(6,3)*factorial(20)/factorial(26)*(13*12*11)^2
外面7张,4-3分布的概率62.18% 2*choose(7,3)*factorial(19)/factorial(26)*(13*12*11)^2*10
外面8张,4-4分布的概率32.72% choose(8,4)*factorial(18)/factorial(26)*(13*12*11*10)^2