Mattress Mack is playing the most secretive of games going into a pivotal Game 7 of the ALCS between his beloved Houston Astros and the visiting Texas Rangers.

“Deep secret,” Mack said to Action Network’s Darren Rovell after he was asked how much he has invested and how much he stands to win.

That’s a stark contrast to last year when Mack was outwardly boasting last season about his victory, winning briefcases filled with money — a comfy $75 million payday and a record for one wager in the legal sports betting market.

But this year things are different for the 72-year-old.

Whether it is for financial purposes or just wanting less public attention, Jim “Mattress Mack” McIngvale is holding his chess pieces extremely close to his chest.

Mack had at least $43.4 million riding on the Astros to win the World Series on $6.9 million wagered throughout the legal market as of last week, with Caesars Sportsbook taking a significant portion of that action.

According to Rovell, he has upped that investment to $7.9 million while standing to win $50.9 million.

His latest MLB wager was taken on FanDuel Sportsbook after the Astros went down 2-0 in the ALCS.

Here are the bets that we know about, with other unknown bets possibly on the line.

The Astros face ex-Mets ace Max Scherzer in Houston on Monday in Game 7, where Mack will be on pins and needles hoping for another postseason blow up in front of a raucous crowd.