Fritz Fred Peterson (born Fred Ingels Peterson February 8, 1942, in Chicago, Illinois) was a Major League Baseball player for the New York Yankees, Cleveland Indians and Texas Rangers from 1966 to 1976. 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. Peterson will also go down in the history of the original Yankee Stadium as having recorded the lowest overall ERA of 2.52.

From 1968 to 1972, Peterson led the league in control every year, with as few as 1.23 walks per nine innings in 1968. In 1969 and 1970, he had the best strikeout-to-walk ratios in the American League. In 1970 and 1975, he had the 10th-best won-lost percentages in the league.

However, he is better remembered today for swapping families with fellow Yankee pitcher Mike Kekich, an arrangement the pair announced at spring training in March, 1973. Peterson and Kekich had been inseparable friends since 1969; both families lived in New Jersey, their children were about the same age, and often they all would visit the Bronx Zoo or the shore or enjoy a picnic together. They decided that they would one day trade wives, children, and even dogs.

The affair began in 1972, when the two couples joked on a double date about wife swapping, a phenomenon that caught on in some uninhibited circles during the early 1970s. According to one report, the first swap took place that summer, after a party at the home of New York sportswriter Maury Allen. The couples made the changes official in October; Kekich moving in with Marilyn Peterson and Peterson with Susanne Kekich, but no word leaked out until spring of 1973.

The trade worked out better for Peterson than it did for Kekich, as Peterson is still married to the former Susanne Kekich, with whom he has had four children. Kekich and Marilyn Peterson did not last long.[citation needed]

Peterson's pitching seem to suffer in 1973 and 1974 after this "deal," and he was roundly booed in nearly every American League ballpark afterwards. In April, 1974, the Yankees traded him to the Cleveland Indians.

Peterson later did color commentary for the New York Raiders WHA professional hockey franchise during the 1972-73 season.

Later, Peterson and Susanne Kekich were living outside Chicago, where he worked as a boat dealer.

Peterson is also notable for his appearances in Jim Bouton's bestselling 1970 non-fiction book, Ball Four, where he is generally portrayed as one of the few major leaguers and former Yankees that had a positive view of Bouton.

http://en.wikipedia.org/wiki/Fritz_Peterson