1966 Topps #309 Diego Segui
About Diego Segui
Segui's 1966 Topps card, #309, sits in the set's fourth series. It pictures him as a Kansas City Athletic after a 5-15, 4.64 season in 1965 for a club that lost 103 games and finished last again. Executive vice president Ed Lopat, unhappy with the record, cut his salary, and pitching coach Cot Deal made him a special project that spring at Bradenton, convinced the forkball was outstanding and that only the delivery and control needed work. The attention did not save the job: on April 13, 1966, days into the season, Kansas City sold him to the Washington Senators, so the uniform on this card was already out of date.
Diego Segui, a right-handed forkball specialist born in Holguin, Cuba, pitched in the majors from 1962 to 1977 for the Kansas City and Oakland Athletics, Washington Senators, Seattle Pilots, St. Louis Cardinals, Boston Red Sox, and Seattle Mariners. Signed by Cincinnati in 1958 and released that April, he was sold to the Athletics by Tucson in September and worked up their farm system before debuting on April 12, 1962. He finished 92-111 with a 3.81 ERA, 71 saves and 1,298 strikeouts, and led the American League with a 2.56 ERA for Oakland in 1970. His only World Series work came in relief for Boston in Game Five of 1975, a series Cincinnati won in seven games. He is the only man to play for both Seattle franchises, pitching in relief in the Pilots' first game in 1969 and taking the loss in the Mariners' first game on April 6, 1977, the start that earned him the name 'the Ancient Mariner.' He later pitched a decade in the Mexican League and still holds the Venezuelan winter league career strikeout record, which brought him induction into the Venezuelan Baseball Hall of Fame in 2003. His son David Segui also reached the majors. Segui died in 2025 at 87.
Sources: SABR BioProject · Baseball-Reference · Baseball Almanac (1) · Baseball Almanac (2)
Graded population (PSA & SGC)
| Grader | Total | 10 | 9 | 8 | 7 | 6 | 5 | 1-4 | Auth |
|---|---|---|---|---|---|---|---|---|---|
| PSA | 167 | 1 | 23 | 90 | 28 | 15 | 3 | 7 | 0 |
| SGC | 3 | 0 | 0 | 2 | 1 | 0 | 0 | 0 | 0 |
Graded population — a scarcity guide, not a price. Data as of 2026-09-04. Half grades fold down for both graders (8.5→8); PSA qualified slabs (OC, ST, PD, MC and the like) are not counted. Where SGC registers no separate row for a variation state, its slabs of that card are listed under the base state.
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Related cards
Team card: #492 Kansas City Athletics
More Kansas City Athletics cards:
- #18 Roland Sheldon
- #36 Jim Hunter
- #55 Ken Harrelson
- #74 Don Mossi
- #107 Athletics 1966 Rookie Stars
- #143 Jose Tartabull
- #157 Rene Lachemann
- #175 Bert Campaneris
- #201 Jim Dickson
- #236 Mike Hershberger
- #256 Lew Krausse
- #287 Jack Aker
- #332 Billy Bryan
- #366 Wayne Causey
Frequently asked questions
What is the 1966 Topps #309 card?
It is card #309 of the 598-card 1966 Topps Baseball set, picturing Diego Segui of the Kansas City Athletics.
How many cards are in the 1966 Topps Baseball set?
598 cards, tracked as 613 collectible states. Numbers run from 1 to 598 with no gaps and no number used twice, and 14 cards carry catalogued print variations - five checklists, the trade and sold statement backs, the three-state #43 Don Landrum, three team-card dot pairs and the #161 Jerry Lumpe white streak - that the master set counts separately.
Sources: Trading Card Database, PSA CardFacts, Cardboard Connection, Baseball Almanac, Baseball-Reference, the SABR BioProject and the National Baseball Hall of Fame, PSA & SGC population reports. Card data compiled and maintained by T206Cards.com. Page last updated 2026-10-11.