do not choose a strategy

不要选择这样的策略
do not choose a strategy that is never a best response to any belief.

不要选择任何信念下都非最佳对策的策略
Notice here, just to underline something

我再提一下上一讲最后的结论
which came up at the end last time,

大家需要引起重视
that doesn't just mean beliefs of the form,

我并不是说信念是这种形式的
the goalie's going to dive left or the goalie's going to dive right.

即门将会扑向左路或者门将会扑向右路
It means all probabilities in between.

它包含了所有可能下的概率
So we're allowing you to, for example, to hold the belief that

所以打个比方这里也可以包括
it's equally likely that the goalie dives left or dives right.

门将扑向左右两路概率相同的情况
But if there's no belief that could possibly justify it, don't do it.

但任何信念下这么选都不合理
And underlining what arises in this game,

我们从这个博弈中可以得出
notice that in this game we're able to eliminate one of the strategies,

我们能够剔除其中的一个策略