OAKLAND — These Oakland Athletics never count themselves out — down and doubted is their dogma. Brett Anderson outdueled fellow postseason first-timer Anibal Sanchez and the upstart A’s were stellar on defense all over the diamond, avoiding another playoff sweep by Detroit by beating the Tigers 2-0 Tuesday night in their AL division series. The A’s cut their deficit in the best-of-five matchup to 2-1. Coco Crisp saved a likely home run by Prince Fielder with a leaping catch at the top of the center-field wall in the second — and the A’s will play another day in this improbable …