this is how Venus and Serena play,

维纳斯和塞丽娜就应该这样打网球
Venus and Serena know each other perfectly well,

她们互相太了解对方了
they know that they mix this way,

她们知道对方的混合策略
they're going to best respond to it,

她们都想要采用最佳的对策
this is going to be where they end up.

则这就是她们的最后选择
But in the meantime, serena hires a new coach

然而就在此时塞丽娜雇了一个新教练
and Serena's new coach is just very, very good at teaching Serena

他特别擅长教会塞丽娜如何打球
how to play at the net, and in particular, how to hit the backhand volley.

特别是教塞丽娜如何打反手球
So Serena's new coach, let's say it's Tony Roche or somebody,

假如塞丽娜的新教练就是托尼·罗切
it's just a brilliant coach

他真是一位好教练
and Tony Roche is able to improve Serena's backhand volley

他提高了塞丽娜打反手球的水平
and that changes these payoffs.

由此也就改变了这些收益