Early first base mitt designs in the 1880s became specialized from the padded fielder’s glove to an oven mitt design.
Many variations in the webbing between the fingers and the thumb existed. Some mitts had a simple crisscross lace and others had a simple leather strap with a buckle adjustment. The back of the hand fashioner varied as well with some mitts having a buckle back strap or the more standard strap with a button. The mitt changed little until the late ‘30s when ¬forces would come together to revolutionize mitts and gloves forever.
Hank Greenberg “Hamming Hank” was an outstanding slugger with the Detroit Tigers in the ‘30s and ‘40s coming within a couple of home runs of tying Babe Ruth for the single season home run record in 1938. He is a member of the Baseball Hall of Fame. Less known was that Hank Greenberg was an outstanding first baseman and baseball glove innovator. Together, he and Rawlings designer Harry Latina extended the size of the typical baseman’s mitt to 13” and added an extra flap between the thumb and the fingers and a cross-lace. Up until then all gloves were designed basically as padding for the receivers non-throwing hand used just as an absorber for the thrown ball, then the fielder would secure the thrown or hit ball with his the bare throwing hand. Generally, a fielder needed to use two hands to receive a ball. The mitt innovation gave Greenberg a great catching advantage. Now with the new mitt Greenberg could snare a thrown ball easily with just the one mitted hand. The new mitt was so good that the Major league Rules Committee outlawed Greenberg’s fishnet web device in 1939 because it was excessively large. After that, new rules restricted the size of the mitt to no bigger than 12”. Latina patented and added the new design to the Rawlings catalog in 1941 as a 12” pattern. The T-70 “Trapper” became the prototypical mitt for all and every first basemen. Patented and so popular was the “Trapper” that Rawlings made the mitt for most other manufacturers including: Wilson, MacGregor and Spalding in the 50s. The “Trapper” also known as the “Claw,” would change all gloves and mitts in future designs in that they incorporated the Greenberg/Latina innovative features.