Peterson was a southpaw starting pitcher who enjoyed his best success in 1970 with the Yankees when he went 20–11 and pitched in the All-Star game.
In twelve games (ten starts), he had a 4–3 win–loss record with a 4.43 earned run average (ERA); he struck out 80 batters in 61 innings pitched.
In 21 games started, Peterson amassed a 10–7 record, with a 2.73 ERA; he struck out a team-leading 194 batters in 155 innings.
[5] He played winter ball in the 1964 Florida East Coast Instructional League; he had a 7–2 record with a 1.68 ERA, striking out 45 batters in 59 innings.
[6] Assigned to the Greensboro Yankees of the Class A Carolina League in 1965, Peterson had an 11–1 record in fourteen starts, with a 1.50 ERA, and 83 strikeouts in 108 innings.
[7] Yankees minor league pitching coach Cloyd Boyer was credited with helping Peterson become a star pitcher.
[3] Yankees manager Johnny Keane was high on Peterson, telling reporters that he averaged three strikeouts for every walk in the minors.
Before a crowd of 35,624 at Memorial Stadium in Baltimore, Peterson pitched a complete game, striking out three batters and walking none.
[9] "Where the vintage pitchers like Whitey Ford, Pedro Ramos, and Bob Friend had failed, Frederick (Fritz) Peterson succeeded yesterday for the New York Yankees.
In his first major league game, the 24-year-old left-hander beat the Baltimore Orioles, 3–2, and drew an accolade from his manager, Johnny Keane," the New York Times wrote of his debut.
The American League team was leading 4–1 in the bottom of the ninth inning when Catfish Hunter gave up a home run and two singles.
The Yankees traded Peterson, Steve Kline, Fred Beene, and Tom Buskey to the Cleveland Indians for Chris Chambliss, Dick Tidrow, and Cecil Upshaw on April 26, 1974.
[16] After a 0–3 start with a 5.55 ERA in nine games, the Indians traded Peterson to the Texas Rangers for Stan Perzanowski and cash on May 29, 1976.
[18] Peterson and fellow Yankee pitcher Mike Kekich swapped wives and children, an arrangement the pair announced at spring training in March 1973.
"[21] Peterson provided color commentary for the New York Raiders of the World Hockey Association during the 1972–73 season.
[22] Later, Peterson and Susanne Kekich lived outside Chicago, where he worked as a blackjack dealer at the Grand Victoria Casino in Elgin, Illinois.
[32] In April 2018, Peterson revealed in an interview with the New York Post that he had been diagnosed with Alzheimer's disease in September 2017.