You can do a better job of bluffing if you hold your cards close to your vest.

VOA: special.2009.11.22

You want to use "it is important to" to emphasize or to make note of something that you hold close.

你使用“it is important to”来强调或说明你认为很重要的事情。

It's important 课堂 - SpeakingMax英语口语达人

You hold your cards close to you so no one can see what you have.

VOA: special.2009.11.22

This region could hold close to 6 billion barrels of oil that have yet to be discovered.

FORBES: Arctic Chill As Norway And Transocean Try To Offset Production Declines

Foreign investors hold close to half of Malaysia's government debt, a testament of trust in the steady economic progress that has helped lift millions out of poverty.

WSJ: Malaysians Turn Out in Large Numbers in Tight, Historic Election

Last year's Giants-Patriots clash had everything working for it--two major markets, an undefeated team (New England) playing for a place in history and a close game to hold viewers curious to see whether the Giants could pull off the upset (they did).

FORBES: Magazine Article