Hubbell was born in Carthage, Missouri. Nicknamed "King Carl" by the fans and "The Meal Ticket" by his teammates, Hubbell's first major-league victory was a 4-0 shutout of the Philadelphia Phillies. Making a late entry to the majors at age 25, Hubbell would go 10-6 in his first season, and would pitch his entire career for the Giants. With a slow delivery of his devasting screwball, Hubbell recorded five consecutive 20-win seasons for the Giants (1933-37), and helped his team to three NL pennants and the 1933 World Series title. In the 1933 Series, he won two complete game victories, including an 11-inning 2-1 triumph in Game Four (the run was unearned). In six career Series starts, he was 4-2 with 32 strikeouts and a low 1.79 earned run average.
Template:MLB HoF In the 1934 All-Star game played at the Polo Grounds, Hubbell set a record by striking out Babe Ruth, Lou Gehrig, Jimmie Foxx, Al Simmons and Joe Cronin in succession: five batters destined for Cooperstown. In 1984, the 50th anniversary of this legendary performance, the National League pitchers Fernando Valenzuela and Dwight Gooden combined to fan six batters in a row for a new All-Star Game record (future Hall of Famers Dave Winfield, Reggie Jackson, and George Brett by Valenzuela; Lance Parrish, Chet Lemon, and Alvin Davis by Gooden). Hubbell himself was on hand for the 1984 All-Star Game at San Francisco's Candlestick Park to throw out the first pitch (a screwball of course).
After his retirement, Hubbell served as director of the Giants' minor league organization and director of player development for 35 years. The last 10 years of his life were spent as a Giants scout.
He died due to injuries sustained in an auto accident in Scottsdale, Arizona at 85 years of age. Hubbell is interred in Meeker-Newhope Cemetery in Meeker, Oklahoma.
- Won 16 straight games (1936) (and 24 over two seasons)
- Twice named National League MVP (1933, 1936)
- 9-time All-Star (1933-38, 1940-42)
- 3 times led the league in wins: 1933 (23), 1936 (26), 1937 (22)
- 3 times led the league in ERA: 1933 (1.66), 1934 (2.30), 1936 (2.31)
- Led the league in innings pitched, 1933 (308)
- Led the league in strikeouts, 1937 (159)
- Led the league in strikeouts/9 innings pitched, 1938 (5.23)
- Led the league in shutouts, 1933 (10)
- Led the league in saves, 1934 (8, retroactively credited)
- Compiled a streak of 46 1/3 scoreless innings and four shutouts (1933)
- Pitched a no-hitter against the Pittsburgh Pirates (11-0, May 8, 1929)
- Pitched a 18-innings shutout against the St. Louis Cardinals (1-0, July 2, 1933)
He inspired many players in the future, as well as his nephew Darrin Hubbell. Darrin made it very far in baseball, but decided that he would much rather become a manager at the world famous resturant "Hard Rock Cafe"