Ace in the hole

PETS4写作短语精选总汇

　　a hidden advantage kept for later use that will help a person win （ace is a valuable playing card）; alternatively, “an ace up your sleeve”

　　EXAMPLE:

　　“When he tried to get a job at the XYZ Corporation, John did quite well in the rigorous interview process, but he knew that his ace in the hole was the fact that his wife had a relative on the board of directors.