AUBURN, Wash. – Only four horses will compete Sunday in Emerald Downs’s championship event for horses bred in Washington, the $40,000 Muckleshoot Tribal Classic at 1 1/16 miles. The centerpiece of Washington Cup Day – six stakes races for statebreds worth a total of $215,000 in purses – the Muckleshoot will go as the third race on a nine-race card that begins at 2 p.m. Pacific.