And b, they have what's called a low expense ratio since they're easy to implement, you don't pay anyone to be brilliant to implement if for you.

但是他们的费用比率很低,因为这种做法很容易，你不需要,有多聪明就能去实施。

麻省理工公开课 - 计算机科学及编程导论课程节选

So the easy ones are on the diagonal: you both get B- if we both choose Alpha; we both get B+ if we both choose Beta.

这样就更直观了,如果我们都选α的话得B-,如果我们都选β的话得B+

耶鲁公开课 - 博弈论课程节选