I'm not sure it does compress the range.

但是我不太确定这是否压缩了范围

耶鲁公开课 - 博弈论课程节选

I personally don't like swings that much and it's the B-/B+ range, so I'd much rather prefer that to a swing from A to C, and that's my reason.

我不喜欢成绩波动很大的,比如B-/B+这个范围,所以我还是喜欢像A到C这样小点的,这就是我的原因

耶鲁公开课 - 博弈论课程节选