SAN FRANCISCO — Since signing with the San Francisco Giants, most of Alex Cobb’s first season here has been derailed by poor defense or health issues. His expected ERA: sterling. The actual number: not so much. Opening a three-game weekend series with the Chicago White Sox on Friday, Cobb finally got the results to match. He went five shutout innings in possibly his best start in orange and black, but the Giants were shut out for the fourth time this season and lost anyway. On a home stand that featured two last-place teams and one in town now that has underachieved, the Giants have lost four …
