Swing, hit, run, slide into home. That’s essentially all there is to baseball, right? Wrong. The sport’s far more complex than that, thanks in part to the “Laws of Base Ball,” a collection of 23 historic documents from 1857 that established some of the sport’s essential rules. Last Sunday, these early instructions became one of history’s highest-priced pieces of sports memorabilia, The New York Times reports, thanks to an anonymous bidder who acquired the seminal papers via online auction for a staggering $3.26 million.

SCP Auctions, which described the rules as the “Magna Carta of our national pastime,” was responsible for the sale. Bidding began on April 6, and lasted for just over two weeks.

Daniel “Doc” Adams, president of the New York Knickerbocker Base Ball Club, wrote the “Laws” in January 1857 when 14 baseball clubs met in New York City to codify rules for the sport, The Guardian writes. Today, Adams is credited with creating many of the game’s fundamental instructions, including nine men on a side, 90-foot base paths, and nine innings to a game.

For years, the "Laws of Base Ball" were owned by the family of William Grenelle, a Knickerbockers delegate to the 1857 convention. An anonymous buyer purchased the documents in 1999 for $12,000; he didn’t know their true value until the auction house appraised them and predicted they would sell for more than $1 million, the Associated Press reports

Think $3.26 million is a lot of money? Believe it or not, die-hard baseball fans have shelled out even more cash for prized relics from the sport's history. In 2012, Babe Ruth’s 1920 New York Yankees jersey sold for $4.4 million. In 2010, James Naismith's 1891 "Founding Rules of Basketball" sold for $4.3 million, The Guardian points out.