Fat chance 不可能，没门儿 是一种讽刺(sarcastically)的说法

　　A: Are you going to buy me a new coat for Christmas?你会给我买件新外套当做圣诞节礼物吗?

　　B：Fat chance!没门儿!

　　可能性

　　有一半的可能性

　　I think it’s 50/50.

　　We have a50/50 chance.

　　几乎不可能

　　There is no hope.

　　There is no possibility.

　　There is no chance.

　　Chance vs. Opportunity

　　Chance 是一种偶然的机会

　　Opportunity 是一种被给予、被许可的机会。

　　I was never given the opportunity of going to college.我从来都没有机会上大学。

　　She left and I missed my chance to say goodbye to her.她走了，我错过了跟她说再见的机会。

　　This is a good opportunity to get a promotion.这是个升职的好机会。

　　This is a too good chance/opportunity to be lost.这是个不容错失的好机会。

　　Yes. It’s my fault. So please give me a one more chance.是我的错，请再给我一次机会。