keep cards close to chest

keep/play your cards close to your chest

to not tell anyone what you plan to do I never know what Martin's next move will be. He plays his cards close to his chest.

Name	Pronounced	Usage
Robyn	['rɔbin]
'Ovadyah	-	Biblical Hebrew
Aparna	-	Hinduism, Indian, Hindi, Marathi, Malayalam, Tamil, Kannada, Telugu, Bengali
Allochka	-	Russian
Balthazar	[bæl'θæzə]
Faustina	[fɔ:'sti:nə]