Randall David Johnson (born September 10, 1963), nicknamed "The Big Unit", is an American former professional baseball pitcher who played 22 seasons in Major League Baseball (MLB), from 1988 to 2009, for six teams.
He played primarily for the Seattle Mariners and Arizona Diamondbacks.
His 303 career victories rank as the fifth-most by a left-hander in MLB history, while his 4,875 strikeouts place him second all-time behind Nolan Ryan and are the most by a left-hander.
He holds five of the seven highest single-season strikeout totals by a left-hander in modern history.
Johnson won the Cy Young Award five times, second only to Roger Clemens' seven, and he is one of only two pitchers (the other being Greg Maddux) to win the award in four consecutive seasons (1999–2002).
In 1999, he joined Pedro MartĂnez and Gaylord Perry in the rare feat of winning the award in both the American and National Leagues (a feat since accomplished by Clemens, Roy Halladay, and Max Scherzer).
He is also one of five pitchers to pitch no-hitters in both leagues.
On May 18, 2004, at the age of forty, Johnson became the oldest pitcher in major league history to throw a perfect game, and is one of seven pitchers who have thrown both a perfect game and a no-hitter in their careers.
He is also one of eighteen pitchers in history to record a win against all 30 MLB franchises.
On May 8th 2001, Johnson achieved the feat of striking out 20 batters in one game, doing so against the Cincinnati Reds.
One of the tallest players in major league history at 6 feet 10 inches (2.08 m), and a ten-time All-Star, Johnson was celebrated for having one of the most dominant fastballs in the game.
He regularly approached – and occasionally exceeded – 100 miles per hour (160 km/h), during his prime.
Johnson also threw a hard, biting slider.
After struggling early in his career (having won only 64 games by his 30th birthday), he went on to lead his league in strikeouts nine times, and in earned run average, winning percentage, and complete games four times each.
Johnson was named one of two (along with Curt Schilling) World Series Most Valuable Players in 2001, with three pitching victories, leading the Diamondbacks to a World Series championship over the New York Yankees in only Arizona’s fourth season.
He won the pitching Triple Crown in 2002.
Johnson's .646 career winning percentage ranks sixth among left-handers with at least 200 decisions; among southpaws, he ranks eighth in games started (603) and ninth in innings pitched (?4,135 1/3).
Johnson’s career elite rankings also include: first in strikeouts per nine innings pitched (10.67), third in hit batsmen (188), and tenth in fewest hits allowed per nine innings pitched (7.24).
He was elected to the Baseball Hall of Fame in 2015, his first year of eligibility, and is the first member of the Hall to be depicted in a Diamondbacks uniform on his plaque.