Babe Ruth is poised to hit another home run, only this time on the sports memorabilia market when the bat he used to slug No. 500 nearly a century ago hits the auction block on Wednesday.

Known as the "Sultan of Swat" during a storied Major League Baseball career Ruth, who passed away in 1948, is now the King of Memorabilia, with the ash bat the New York Yankees slugger used on August 11, 1929 to become the first player to hit 500 homers expected to fetch well over a million dollars.

For any serious collector, no showroom is complete without at least one item connected to "the Babe."

Of the top 20 highest priced sports memorabilia items almost half (nine) have the Ruth name attached to them.

In June, a Yankees jersey worn by Ruth went for 5.64 million U.S. dollars, making it the most expensive piece of sports memorabilia ever sold, while the bat he used to slam the first ever home run at Yankee Stadium sold in 2004 for 1.26 million U.S. dollars.

Online bidding for the Louisville Slugger used to swat number 500 begins November 27. By the time it closes on December 14, it will almost certainly find a spot in the top 10.

"We're estimating this at a million and up just to be conservative," David Kohler, president of SCP Auctions, which will conduct the sale, said. "We think it will surpass the other bat. This 500 bat is kind of the brother to it."

"Even though he has been gone since 1948 he remains the King," Kohler said.

There is genuine excitement in the collector world as what is known as "a fresh piece" makes its way to market.

Unlike some items that have changed hands several times, Ruth's 500th home run bat has spent decades out of sight in undisturbed solitude.

Ruth gifted it some time in the mid-1940s to the mayor Suffern, New York, Jim Rice, a golfing, bowling and drinking buddy of one of baseball's original Hall of Famers.

For decades the historic bat leaned impassively in a corner of the Rice family den, treated not as a piece of history but more like a piece of furniture no different than the bookcase and coffee table.

After Jim and then his wife passed away, the bat spent three decades hidden in a closet in the home of their only son Terry.

The childhood joy Terry had reveled in from owning such a sporting treasure has given way to dread, the bat too valuable to display or even tell anyone about.

"It just got to the point I couldn't leave it out," Rice told Reuters. "I was less cautious years ago but more recently I hardly told anybody.

"I just couldn’t enjoy it, it was hidden away. My girlfriend was afraid to have it here, that somebody would break in so we weren't enjoying it.

"It just seemed time," he said.