What makes this Ruth, Mays, and Aaron card so important?

 It's card number one in the 1973 set. It's one of the key cards to the set, and features three of baseball's greatest hitters. Take Mr. Steroids out of the picture, and you still have the all time home run leaders, just in a different order.

But that's not all that's important: that card was one of hundreds from the 1973 set given to me by Jim - who started out as a local reader with some cards for my collection and is now a friend. We've met up a few times now and it's always great to get together with him and talk baseball and cards.

You want to know how many cards he sent? See the image below:

I don't know how I'll ever repay you, Jim, for this *awesome* stack of cards. I believe that comprises about 30% of the set. So thank you again!