Late in 1937 Hugh Alexander, a kid fresh out of small-town Oklahoma, had just finished his second year playing outfield for the Cleveland Indians when an oil rig accident ripped off his left hand. Within three months he was back with the Indians, but this time as a scout the youngest ever in Major League history. In the next six decades he signed more players who made it to the Majors than any other scout.

His story, Baseball s Last Great Scout, reads like a backroom, bleacher-seat history of twentieth-century baseball and a primer on what it takes to find a winner. It gives...