Hold aces is an idiom that is often used to express an advantageous position in a particular situation. The term originally comes from the game of poker where having an ace in hand provides the holder with an advantage over others. Many synonyms that convey a similar idea to 'hold aces' could be used in different situations, such as 'being in the driver's seat,' 'having the upper hand,' 'calling the shots,' 'being in control,' 'having the edge,' or 'having an advantage.' All of these expressions emphasize that someone is in a favorable position or has an advantage over others, much like holding aces in a game of poker. Ultimately, there are many phrases in the English language to describe an advantageous position that varies depending on the context.