Fat chance

[bread]

Does "fat chance" have two meanings? It seems that if someone has a fat chance of winning, he/she stands a good chance; however, "fat chance" means "no chance," according to different dictionaries. I am entirely confused... Does "fat chance" mean differently when the speaker says it with different tones?

Thank you.

[Casiopea]

Does "fat chance" have two meanings? It seems that if someone has a fat chance of winning, he/she stands a good chance; however, "fat chance" means "no chance," according to different dictionaries. I am entirely confused... Does "fat chance" mean differently when the speaker says it with different tones?

Thank you.

I've not heard of the first usage, but I can see how one might use it to mean, the chances of winning are great. I've heard the second usage only, the chances of losing are great.