APA 2020 2021 SL 9 Patch American Pool Players Association League The APA 2020 2021 SL 9 Patch is an official patch representing the American Pool Players Association League. Made by the APA, the patch is a collectible item that can be sewn or adhered to various surfaces to show support for the league or to resemble a player's license. This accessory is perfect for fans of billiards looking to showcase their love for the sport and the APA.