Aiken's fastball hit 97 mph this spring. He is 6-foot-3, 210 pounds is committed to UCLA. Baseball America quoted one scout saying his curve was "silly good."
With the No. 1 overall pick in each of the previous two drafts, the Astros selected Stanford right-hander Mark Appel in 2013 and Puerto Rican high school shortstop Carlos Correa in 2012. Both are playing for high Class A Lancaster (Calif.) this season.
The only other high school left-handers chosen No. 1 overall were David Clyde by the Texas Rangers in 1973 and Brien Taylor by the New York Yankees in 1991. Clyde had a mediocre career. Taylor got injured and never made the majors.