Scott is part of a select group of pitchers that have thrown a no-hitter and struck out 300 batters in the same season.

Craig taught Scott the split-finger fastball, a pitch he had made famous while coaching the pitchers of the 1984 World Series champion Detroit Tigers.

In August 1986, Roger Craig, then the manager of the San Francisco Giants, complained that Scott's real secret was that he scuffed the baseball.

"[2] Scott had his most successful season in 1986, when he posted an 18–10 record with a 2.22 earned run average, striking out a league-leading 306 batters.

[3][4] On September 25 of that season, he threw a 2–0 no-hitter against the San Francisco Giants at the Astrodome to clinch the National League West division title for the Astros.

[5] He led a strong starting rotation that included Bob Knepper, Nolan Ryan, and Jim Deshaies.

Scott's outstanding form continued into the postseason, when Houston faced the Eastern Division champion New York Mets in the 1986 National League Championship Series.

The Mets aggressively voiced their suspicions that Scott was doctoring the baseball to the media during the series, although nothing was ever found to support these claims.

He went 16–13 with a 3.23 earned run average, eight complete games and three shutouts in 247.2 innings while finishing second in the National League with 233 strikeouts.

In 1989, Scott won 20 games (while losing 10) and finished second in NL Cy Young Award voting, behind reliever Mark Davis of the San Diego Padres.