Checker's name is actually Shake, he is out of the real Checker, who is out of Tetley. On the mother's side he goes back to Boots who is Typhoon's father. Boots was a super dog from Frank Kelly who goes back to Victor and Sailor ( Saunderson)
Raymond Cook bought a female out of Boots from Frank early 2000's and bred to Checker (the real Checker) and got Shake.