Park developed into the best Rangers defenceman, whose offensive skill, stickhandling and pugnacity made him popular with local fans and media. He even drew occasional comparisons with the Boston Bruins superstar Bobby Orr, universally acclaimed to be the greatest at his position in hockey history. Years afterward, Park remarked, "I saw no reason to be upset because I was rated second to Bobby Orr. After all, Orr not only was the top defenceman in the game but he was considered the best player ever to put on a pair of skates. There was nothing insulting about being rated No. 2 to such a super superstar."

Park was made the alternate captain of the Rangers and briefly served as their captain. In 1972, after the team's top scorer, Jean Ratelle, was lost due to a broken ankle, he led the Rangers past the defending Stanley Cup-champion Montreal Canadiens in the first round and the West Division champion Chicago Black Hawks in the semifinals of the playoffs. The Rangers advanced to the Stanley Cup finals where they fell to the Boston Bruins in six games. After the Rangers staved off elimination in Game 5 at Boston, Bruins assistant captain Phil Esposito said famously, "If the Rangers think they're going to beat us in the next two games, they're full of 'Park' spelled backwards," Sure enough, the Bruins put them away in Game 6 at Madison Square Garden. Park finished a distant second to Orr in the Norris Trophy vote.

When the upstart World Hockey Association tried to lure Park away, the Rangers re-signed him to a $200,000-a-year contract that made him, briefly, the highest-paid player in the NHL.

In the 1972 Summit Series, with Orr unable to play due to injury, Park emerged as a key contributor to Team Canada's series over the Soviets, being named Best Defenceman of the series.

After opening the 1975–76 season with their worst start in ten years, the Rangers began to unload its high-priced veterans. Park, along with Jean Ratelle and Joe Zanussi, was traded to the Boston Bruins in a November 7 blockbuster deal that also sent Phil Esposito and Carol Vadnais to the Rangers, one that shocked everyone.^[5][6] The New York press and public had felt that Park, 27 at the time, was overweight, overpaid and over the hill, as he was facing unfavorable comparisons to Denis Potvin.

Honours and achievements:

• Named to the first All-Star team in 1970, 1972, 1974, 1976 and 1978.
• Named to the second All-Star team in 1971 and 1973.
• Runner up in Norris Trophy voting in 1970, 1971, 1972, 1974, 1976 and 1978
• Received both the most First Team All-Star nominations (other than Earl Seibert, who retired before the trophy was awarded) and was runner-up for the Norris more times without winning the Norris than any other defenceman in NHL history.
• Played in the NHL All-Star Game in 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977 and 1978.
• Won the Bill Masterton Memorial Trophy in 1984.
• The book 'Play the Man' (Dodd, Mead, & Co.) written by Brad Park and Stan Fischler was published in 1971.
• Retired as the leading defence scorer in Rangers' history and the second leading defence scorer in Bruins' history to Bobby Orr.
• At the time of his retirement, had played the most seasons in league history for a player never missing the playoffs.
• Currently 13th all-time in NHL history in defence scoring.
• Elected to the Hockey Hall of Fame in 1988, in his first year of eligibility.
• Along with Butch Goring, one of the last two active players who had played in the 1960s.
• In 1998, he was ranked number 49 on The Hockey News' list of the 100 Greatest Hockey Players.
• In the 2009 book 100 Ranger Greats, was ranked No. 11 all-time of the 901 New York Rangers who had played during the team's first 82 seasons.

1972 Canada vs Soviet Union