Mackenzie was born on the North channel of Lake Huron in Canada. The man with the thick glasses looked more like a scholar than a ball player, and he actually was. He was a member of the Yale class of 1956, lettering in both baseball and hockey. He went right to AA ball pitching in Atlanta winning 14 games. In his move up to AAA the following year he won 15 games making an impression. In 1959 he became relief pitcher mostly going 6-2 at AAA Louisville making a debut in the big leagues by 1960. He saw action in just 14 games over two seasons in Milwaukee going 0-2 as a Braves reliever.
In October 1961, his contract was purchased by the New York Mets making him an original Met. MacKenzie was a reliever usually coming in the later innings.
Once in a tight game with runner aboard Casey Stengel came out to the mound and told Mackenzie "make out like your pitching against Harvard". MacKenzie shook his head, thinking to himself, Yale is not Harvard.
He would be the first Mets pitcher out of Yale University, until Ron Darling came along twenty years later. Casey was also quoted saying: "He's a splendid young fella with a great education from Yale University. His signing with us makes him the lowest paid member of the class of Yale '56."
Mackenzie made his Mets debut in the fourth game of the team's history, pitching two innings allowing a pair of runs on three hits. After a loss and blown save in May, he went on to earn two straight victories against his old team, on a road trip to Milwaukee.
On May 19th he benefited from a rare Mets hitting outburst as the team scored four runs in the top of the 8th inning. The next day he got more help, when the Mets scored four runs in the top of the 9th inning. Two of the runs scored on an error on Charlie Neal ground ball.
He would actually close out the year winning three of his last four decisions as well. On a team that only won 40 games, MacKenzie pitched at some point or another in ten of those wins. He was the only pitcher on the entire 1962 Mets staff with a winning record (5-4) and his five wins were amazingly third best on the team.
He started out real well in 1963, going 3-0 with two saves posting an 0.82 ERA by early May. He was by far the most successful pitcher on the staff early on. He would make 34 appearances out of the bullpen, blowing two saves, and taking a loss through early August. He was then traded to the St. Louis Cardinals for Ed Bauta on August 5th, 1963.
Over the next two years he would pitch for the San Francisco Giants and Houston Astros, going 0-3 in 31 games combined.
