The Naismith Rules of Basketball
Credit: Chris Hondros / Getty Images

Imagine auctioning off the Constitution. That's what it felt like in 2010 when when James Naismith's Rules of Basket Ball went under the gavel and were sold for $4.3 million. The papers, which lay out the original rules of one of the country's most popular sports, also have handwritten annotations from the sport's founder. The rules went to billionaire David Booth, who sent them to the University of Kansas to inspire the college team. The university is constructing a building where the document will be displayed.

SCP Auctions didn't handle the sale, but it enjoyed the outcome. "Any time a piece of historical sports memorabilia hits a level like that, it's obvious, it shows strength in the marketplace," Imler says. "There was just no precedent for a price at that level."