From 1976 to 1980, he was one of the premier pitchers in the majors, leading the National League twice in strikeouts, once in earned run average, and three times in hits allowed per nine innings, winning at least 18 games a year between 1976 and 1979.

Two-time National League MVPs Johnny Bench and Dale Murphy both named Richard as the toughest pitcher they ever faced.

After his professional baseball career ended, Richard became involved in unsuccessful business deals and went through two divorces, which led to him being homeless and destitute in 1994.

[8] By the time he was a high school senior, Richard stood 6 feet 8 inches (2.03 m) tall and weighed 220 pounds (99.8 kg; 15.7 st).

In one game Richard hit four consecutive home runs while pitching his team to a 48–0 victory against its local rival, Jonesboro's Jackson High School.

[10] Richard, whose baseball idol was St. Louis Cardinals pitcher Bob Gibson, never lost a game he started during his high school career.

[12] Richard later recalled, "There were other guys in my high school with as much ability as I had, but instead of working at a job, they wanted to drink wine on Saturday nights.

[10] During the 1970–71 off-season, the Astros again promoted Richard: this time to Class-AAA baseball, one step below the major leagues, with the Oklahoma City 89ers of the now-defunct American Association.

On September 5, Richard made his major league debut at just 21 years of age, in the second game of a doubleheader against the San Francisco Giants.

[15] Richard was charged with two earned runs and seven hits in the 5–3 Astros win, and struck out Willie Mays and Dick Dietz three times.

[16] Richard made his next start, after five days rest, against the Cincinnati Reds,[17] who would later finish the NL West season in a tie for fourth place with the Astros.

In a September 16 match-up against the Astros' division rival, the third-place Atlanta Braves, Richard pitched seven innings and surrendered four runs on seven hits.

Richard re-entered the majors, starting a day game of a day-night doubleheader for the Astros against the San Diego Padres on July 30, 1972.

[10] Despite his improved performance in the 1973 season, Richard was sent down to work on his pitching mechanics and ball control in Class-AA baseball with the Columbus Astros of the Southern League.

[2] Even though Richard's statistics showed he bounced between Houston and the minors during his first four years with the Astros due to his wildness, he often told reporters that racism played a role in keeping him from becoming a regular with the big club sooner.

[30] In the off-season, the Astros traded starting pitcher Claude Osteen to the Cardinals, and lost pitching ace Don Wilson, who died from carbon monoxide poisoning at the age of 29 on January 5, 1975.

[31] As a result, Richard entered the 1975 season as the third starter of the Astros' pitching rotation, behind veterans Larry Dierker and Dave Roberts.

[2] Richard entered the 1976 season as the pitching staff ace and took over Larry Dierker's position as the Opening Day starter for the Astros.

At age 26, Richard became only the second pitcher in Astros' history (after Dierker in 1969[49]) to record 20 wins in a season, tying him for fourth in the NL that year.

[2] Richard also became the ninth member of the Black Aces, an organization founded by Mudcat Grant that consists of all African American pitchers who have won at least 20 major league games in a season.

[59] In an eight-start period from April 26 to June 4, Richard threw six complete games, including two back-to-back shutouts, and lowered his ERA from 4.15 to 3.05.

[60] By the end of the first half of the season Richard had pitched back-to-back games with nine and 12 strikeout performances, against the Cincinnati Reds and Los Angeles Dodgers, respectively.

[10] He was honored as the National League Pitcher of the Month for September after going 4–1 with a 1.24 ERA, four complete games, two shutouts, and 69 strikeouts in 53 innings pitched during the stretch.

[76] In 1980, Richard was now teamed with seven-time American League strikeout champion Nolan Ryan, who had joined the Astros as a free agent.

After finishing the first half of the season with a 10–4 record, 115 strikeouts and a 1.96 ERA,[78] Richard was selected to be the National League's starting pitcher in the MLB All-Star Game on July 8, but he pitched just two innings due to various back and shoulder problems.

[30] During his next start on July 14 against the Braves, Richard was pitching well and even struck out the side in the second inning, but had trouble seeing catcher Alan Ashby's signs and also had difficulty moving his arm.

[2] Nine days later, he checked into Methodist Hospital in Houston for a series of physical and psychological tests to determine the cause of his mysterious arm problems.

He trained with the Astros and the Texas Southern University team, participating regularly in pitching and batting practice with both toward the end of the baseball season.

In the following months, after spending many nights under the overpass Highway 59 at Beechnut Road in Houston, he turned to the Now Testament Church and sought help from its minister, Reverend Floyd Lewis.

[94] Along with former major leaguers Dick Allen, Mudcat Grant, Kenny Lofton, and Eddie Murray, Richard was honored by the Negro Leagues Baseball Museum as a 2018 member of the "Hall of Game.