Greg Kosc Autographs
Gregory John Kosc (born April 27, 1949) is a former umpire in Major League Baseball who worked in the American League from 1976 to 1999. He officiated in the World Series in 1987 and 1997, and in the All-Star Game in 1981 and 1992. He also worked the American League Championship Series in 1979, 1988 and 1993, and the American League Division Series in 1996 and 1997. Kosc wore uniform number 18 when the American League umpires adopted them in 1980.
Kosc attended UTEP where he competed in weightlifting, hammer throw and shot put.
Kosc and fellow 1976 rookie Al Clark were the first American League umpires who never used the outside chest protector, which had been used since the league's formation in 1901 and was mandated in the 1920s by future Hall of Fame arbiter Tommy Connolly. In 1975, the year before Clark's hiring, the American League ruled umpires could use the outside protector or the National League standard inside protector, invented in the 1910s by another Hall of Fame umpire, Bill Klem. In 1977, the AL ruled all incoming umpires had to use the inside protector, an edict which affected new hires Steve Palermo and Durwood Merrill. Umpires active prior to 1977 using the outside (aka "balloon") protector could continue to use it until they retired or switched to the inside protector.
Read more about Greg Kosc on Wikipedia
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Traded items with a signature of Greg Kosc
The most expensive item with a signature of Greg Kosc (Greg Kosc Signed 1988 T&M Sports #25 IPA In Person Autograph) was sold in February 2026 for $30.98 while the cheapest item (Greg Kosc AL Umpire Signed 3x5 index Card) found a new owner for $0.99 in December 2019. The month with the most items sold (2) was September 2019 with an average selling price of $0.99 for an autographed item of Greg Kosc. Sold items reached their highest average selling price in October 2008 with $30.01 and the month that saw the lowest prices with $0.99 was July 2019. In average, an autographed item from Greg Kosc is worth $5.00.
Most recently, these items with a signature of Greg Kosc were sold on eBay - click here for more items.
| Picture | Item Title | Price | Store |
 | 1970's -Greg Kosc- Signed/Autograph/Auto Index Card Umpire MLB | $7.49 |  |
| 1989 Topps Traded 132T Greg Kosc signed auto autograph MLB Umpire BXCP60 | $13.50 | |
| 1993 Topps Traded 132T Greg Kosc signed auto autograph MLB Umpire BXCP60 | $13.50 | |
| Greg Kosc AL Umpire Signed 3x5 index Card | $0.99 | |
| Greg Kosc AL Umpire Signed 3x5 index Card | $0.99 | |
| Greg Kosc AL Umpire Signed 3x5 index Card | $0.99 | |
| Greg Kosc AL Umpire Signed 3x5 index Card | $0.99 | |
| Greg Kosc AL Umpire Signed 3x5 index Card | $0.99 | |
| Greg Kosc Signed 1988 T&M Sports #25 IPA In Person Autograph | $30.98 | |
| Greg Kosc signed American League umpire card | $6.00 | |
| Greg Kosc Signed Baseball Card with JSA COA | $19.99 | |
| Greg Kosc Signed T&M Umpire Card | $2.50 | |
 | GREG KOSC UMPIRE 1988 T & M SPORTS AUTOGRAPHED SIGNED # 25 | $16.00 | |
 | GREG KOSC UMPIRE 1988 T & M SPORTS AUTOGRAPHED SIGNED # 62 | $16.00 | |
| Greg Kosc Umpire Signed 3x5 index Card | $1.50 | |
