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Seaver was born in Fresno, California, to Betty Lee (Cline) and Charles Henry Seaver. Pitching for Fresno High School, Seaver compensated for his lack of size and strength by developing great control on the mound. Despite being an All-City basketball player, he hoped to play baseball in college. He joined the United States Marine Corps Reserves on June 28, 1962.

On April 22, 1970, Seaver set a major league record by striking out the final 10 batters of the game in a 2-1 victory over the San Diego Padres at Shea Stadium. Al Ferrara, who had homered in the second inning for the Padres' run, was the final strikeout victim of the game. In addition to his 10 consecutive strikeouts, Seaver tied Steve Carlton's major league record, at the time, with 19 strikeouts in a nine-inning game,. The Mets also won the game in which Carlton struck out 19, with Carlton victimized by Ron Swoboda's pair of 2-run homers in a 4-3 Mets victory in St. Louis on September 15, 1969. (The record was later eclipsed by 20-strikeout games by Kerry Wood, Randy Johnson, Max Scherzer, and twice by Roger Clemens.) By mid-August, Seaver's record stood at 17-6 and he seemed well on his way to a second consecutive 20-victory season. But he only won one of his last ten starts, including four on short rest, to finish 18-12. Nonetheless, Seaver led the National League in both ERA and strikeouts.  The 1971 season was arguably Seaver's finest year, when he led the league in ERA (1.76) and strikeouts (289 in 286 innings) while going 20-10. However, he finished second in the Cy Young balloting to Ferguson Jenkins of the Chicago Cubs, due to Jenkins' league-leading 24 wins, 325 innings pitched, and exceptional control numbers. Seaver himself has said that 1971 was his best season.  Seaver had four more twenty-win seasons (20 in 1971, 21 in 1972, 22 in 1975, and 21 in 1977) (7 wins for the Mets, then 14 more after being traded to the Reds). He won two more Cy Young Awards (1973 and 1975, both with the Mets).  During his tenure with the Mets, Seaver made 108 starts in which he pitched 9 or more innings and allowed 1 run or less. His record in those starts is 93-3 with 12 no-decisions. In seven of the 12 no-decisions, he pitched 10 or more innings. In the 12 no-decisions, he pitched a total of 117 innings, allowing 56 hits and 5 earned runs, compiling a 0.38 ERA.  Between 1970 and 1976, Seaver led the National League in strikeouts five of the seven seasons, finishing second in 1972 and third in 1974. Seaver also won three ERA titles as a Met. Two famous quotes about Seaver are attributed to Reggie Jackson: "Blind men come to the park just to hear him pitch." The second was that, while pitching for the Mets during the 1973 World series, 6th game, with the Mets up 3 games to 2, and so poised to win their second Championship, with Mr. Seaver scheduled to start. He did, but did not have his "arm" that day, his arm strength, that is, and the opposing team knew it. Seaver would go on to start and lose the 6th game... Mr. Jackson is reported to have said "Seaver pitched with his heart that day." Seaver was perhaps the foremost latter-day exponent of "drop and drive" overhand delivery, but his powerful legs protected his arm, and ensured his longevity. Seaver was frequently compared to fellow Hall of Fame pitcher Christy Mathewson.
Tom Seaver