The 6 ft 6 in (1.98 m), 195 lb (88 kg) Blackwell is considered to have been one of the greatest pitchers of his era, and starred in a six-year streak in the All-Star Game from 1946 through 1951.

[citation needed] Both Kiner and Hall of Fame catcher Roy Campanella called Blackwell the toughest pitcher they ever faced.

Blackwell's best year was 1947, when he recorded 22 wins against 8 losses, including 16 consecutive complete game victories for a weak-hitting team.

His bizarre sidearm delivery, described by a leading sports pundit as "looking like a man falling out of a tree", put unusual strain on his arm, abbreviating his success and, ultimately, his career.

[citation needed] From 1943 to 1946 during World War II, Blackwell served with the United States Army in Europe where he worked as a mess sergeant.