Today’s idiom is neither violent, nor bloody. It comes from the world of poker and is used in the following discussion between two co-workers who are in the middle of some tough negotiations (Verhandlungen):
„Marion, I don’t know if we can get the seller to lower the price any more.“
„Why not? We’re the last company left in talks with these guys!“
„What? The other potential buyers pulled out?“
„Yeah – Robert was out for lunch today and overheard them talking. They’re done.“
„Well, that’s brilliant – why didn’t you tell me?“
„I wanted to leave that fact unknown for as long as possible. It’s our ace in the hole.“
In one form of poker, some of the cards are left face-down (ungedeckt) on the table. These cards are „in the hole.“ Imagine I have the hand shown above, and the ace is hidden. I have no idea that my hand will beat almost any other hand out there, and exactly that is the meaning of „ace in the hole“ – it’s any useful tactic or fact that remains hidden until it is used to the owner’s advantage.
In German, you would use the phrase „Ass im Ärmel,“ although that phrase suggests that playing the ace gives you an unfair advantage.