The 1911 Western Playground Association set (referred to as H998 in The American Card Catalog) is one of the most obscure sets ever produced. The 2-1/4 x 3-1/2" cards also served as membership certificates into the "Western Playground Association," with the copy on the cards' backs explaining how teachers could redeem the cards for "School Apparatus or Playground Supplies." The cards would be sent from the teacher to the Western Playground Association in San Francisco, which explains the Pacific Coast League tie-in as a west coast company.

This, also, most likely explains why cards from this incredibly unique set are so hard to find today. Only 86 total examples from the 40-card set have ever been graded by SGC. The George Stinson card has only been graded twice, with this offering receiving a grade of Authentic.

Several of the cards in the Western Playground set are labeled as "P.S. League," including this example featuring George Stinson. This is believed to be in error, since all players in the set belonged to the Pacific Coast (P.C.) League. 1911 happened to be the best season of George Stinson's 15-year minor league career. He batted .317 with career highs in hits (177) and doubles (41) for the Class A Vernon Tigers of the Pacific Coast League.