Estock graduated from Warren Harding High School in Bridgeport, Connecticut, in 1942 and was pitching in a summer league afterward when baseball scouts began to notice him.

[1][2] Prior to the 1944 season, the parent Boston Red Sox sent him to the Philadelphia Phillies' organization, and in March 1946 Estock was traded to Pittsburgh Pirates to complete an earlier deal.

He pitched well, giving up three runs in eight innings, but was the loser in what would turn out to be his only big league decision when Cliff Chambers threw a no-hitter against the Braves.

He stayed in baseball until 1955, spending time with the Austin Pioneers, Toledo Mud Hens, Jacksonville Braves, Atlanta Crackers and finishing up with the York White Roses of the Piedmont League in 1955.

At his retirement Estock spoke of his introduction to a future Braves Hall of Famer: "I was pitching batting practice to a young kid who was up for a tryout during spring training in 1952.