In a home run for the SCP Auction House, they sold some of the original rules of baseball for over $3 million dollars, making it the third most expensive piece of baseball memorabilia ever.

The handwritten rules were penned by original New York Knickerbocker Daniel “Doc” Adams in 1857, when 14 clubs came together to write the game’s laws, many of which remain in force today. Among the rules set down in the 23-page Laws of Base Ball: the nine inning game, the nine-person team on the field, and exactly 90-feet between bases.

Prior to the game-changing summit in 1857, baseball, having evolved from older European ball-and-stick games, was governed by a set of rules laid down in 1845 by Alexander Cartwright, who is often referred to as the father of baseball. The 1857 summit and the rules that had come out of it were known to historians thanks to widespread news coverage of the event in its day, but until the discovery of the Laws of Base Ball, no original documentation from the meeting was thought to have survived. More than just being a rare artifact, they also give a key insight into the competing interests and struggles that took place between the clubs.

The documents had survived in a private family collection before being purchased at auction in 1999 in a parcel of other documents. It was not until their original buyer had them appraised for resale that they were discovered for what they were. SCP sold the papers as the “Magna Carta of Baseball,” and their tactics seemed to work: they sold for $3.26 million to an anonymous bidder, making them the single most expensive baseball document ever sold.