The single coolest Topps baseball card from each year: the 1970s

In honor of National Baseball Card Day on Aug. 11, we're selecting the coolest baseball card from every year since Topps' first set in 1951. Rather than simply focus on the most famous or valuable cards, we asked some of the best minds in baseball to provide us with their favorite. It could be because of a great photo, a hilarious story, or just a personal memory they have with the card.
The 1970s were an era of change in baseball. Mustaches returned to the game for the first time in nearly a century, colorful uniforms made their debut and many teams traded grass for turf. For many, this wild, long-haired decade was chronicled in baseball cards. 
Naturally, we turned to Joe Posnanski, a writer who cut his teeth on the '70s Topps and has a very unique way of opening his packs, to rank his favorites.