| 07/11/1985 | Drafted in the 1985 first-year player draft (Round 1, Pick 17, 17th overall pick) by the San Francisco Giants. |
| 07/12/1985 | Signed a minor league contract with the San Francisco Giants organization with a signing bonus of $430,000. |
| 07/21/1985 | Was traded by the San Francisco Giants to the Houston Astros in exchange for $430,000. |
| 08/07/1985 | Injured (mild oblique strain), day-to-day for 1 day. |
| 11/26/1985 | Received a 1-year contract worth a total of $300,000 through automatic renewal. |
| 01/01/1986 | OSA scouting updated ratings (potential): Stuff: 67 (68); Movement: 60 (66); Control: 38 (50). |
| 04/14/1986 | Named the #57 prospect in the ML |
| 12/01/1986 | Received a 1-year contract worth a total of $300,000 through automatic renewal. |
| 01/01/1987 | OSA scouting updated ratings (potential): Stuff: 69 (69); Movement: 60 (66); Control: 38 (50). |
| 04/18/1987 | Pitches a 6-hit shutout against the Cincinnati Reds with 6 strikeouts and 4 BB allowed! |
| 05/27/1987 | Pitches a 6-hit shutout against the St. Louis Cardinals with 7 strikeouts and 1 BB allowed! |
| 07/05/1987 | Was selected to the 1987 Major League Baseball All-Star Game. |
| 11/10/1987 | Wins the 1987 ML NL Cy Young Award. |
| 11/21/1987 | Received a 1-year contract worth a total of $300,000 through automatic renewal. |
| 01/01/1988 | OSA scouting updated ratings (potential): Stuff: 69 (69); Movement: 64 (70); Control: 41 (50). |
| 11/21/1988 | Received a 1-year contract worth a total of $3,800,000 through arbitration. |
| 01/01/1989 | OSA scouting updated ratings (potential): Stuff: 69 (69); Movement: 61 (67); Control: 45 (50). |
| 03/30/1989 | Signed a 3-year contract extension worth a total of $12,000,000 with the Houston Astros organization. |
| 09/16/1989 | Pitches a 4-hit shutout against the Cincinnati Reds with 8 strikeouts and 2 BB allowed! |
| 01/01/1990 | OSA scouting updated ratings (potential): Stuff: 69 (67); Movement: 64 (70); Control: 52 (50). |
| 08/01/1990 | Wins the ML NL Pitcher of the Month Award. |
| 01/01/1991 | OSA scouting updated ratings (potential): Stuff: 68 (67); Movement: 64 (69); Control: 54 (52). |
| 08/02/1991 | Injured (mild shoulder inflammation), out for 1-2 weeks. |
| 01/01/1992 | OSA scouting updated ratings (potential): Stuff: 67 (67); Movement: 67 (71); Control: 56 (53). |
| 04/25/1992 | Signed a 4-year contract extension worth a total of $34,680,000 with the Houston Astros organization. |
| 07/18/1992 | Pitches a 5-hit shutout against the Atlanta Braves with 9 strikeouts and 2 BB allowed! |
| 08/04/1992 | Pitches a 5-hit shutout against the Los Angeles Dodgers with 10 strikeouts and 4 BB allowed! |
| 01/01/1993 | OSA scouting updated ratings (potential): Stuff: 66 (67); Movement: 68 (71); Control: 56 (56). |
| 05/01/1993 | Wins the ML NL Pitcher of the Month Award. |
| 07/18/1993 | Was selected to the 1993 Major League Baseball All-Star Game. |
| 01/01/1994 | OSA scouting updated ratings (potential): Stuff: 66 (67); Movement: 65 (68); Control: 60 (57). |
| 05/13/1994 | Pitches a 4-hit shutout against the New York Mets with 8 strikeouts and 1 BB allowed! |
| 06/01/1994 | Wins the ML NL Pitcher of the Month Award. |
| 06/23/1994 | Was selected to the 1994 Major League Baseball All-Star Game. |
| 08/05/1994 | Pitches a 4-hit shutout against the San Francisco Giants with 4 strikeouts and 1 BB allowed! |
| 01/01/1995 | OSA scouting updated ratings (potential): Stuff: 66 (67); Movement: 64 (67); Control: 56 (57). |
| 04/03/1995 | Collects his 2000th career Major League Baseball strikeout! |
| 08/14/1995 | Pitches a 3-hit shutout against the San Diego Padres with 8 strikeouts and 1 BB allowed! |
| 11/17/1995 | Became a free agent. |
| 01/01/1996 | OSA scouting updated ratings (potential): Stuff: 66 (67); Movement: 67 (70); Control: 59 (59). |
| 03/17/1996 | Signed a 2-year contract worth a total of $21,860,000 with the Texas Rangers organization. |
| 10/17/1996 | Released by the Texas Rangers. |
| 01/01/1997 | OSA scouting updated ratings (potential): Stuff: 65 (67); Movement: 66 (67); Control: 60 (61). |
| 02/14/1997 | Signed a 4-year contract worth a total of $22,000,000 with the Colorado Rockies organization. |
| 08/16/1997 | Collects his 2500th career Major League Baseball strikeout! |
| Year | SH | Rank | | 1988 | 19 | 4 | | 1990 | 17 | 9 | | 1991 | 15 | 9 | | 1992 | 14 | 9 | | 1993 | 15 | 8 | | | Year | GS | Rank | | 1990 | 33 | 9 | | 1993 | 37 | 1 | | 1995 | 33 | 4 | | | Year | W | Rank | | 1987 | 21 | 1 | | 1990 | 17 | 5 | | 1992 | 15 | 9 | | 1993 | 17 | 5 | | 1994 | 18 | 3 | | | Year | L | Rank | | 1986 | 17 | 4 | | 1991 | 15 | 6 | | | Year | Winning % | Rank | | 1987 | .700 | 4 | | 1988 | .600 | 10 | | 1990 | .773 | 1 | | 1994 | .692 | 9 | |
| Year | IP | Rank | | 1987 | 244.0 | 4 | | 1990 | 233.1 | 10 | | 1991 | 244.0 | 8 | | 1992 | 233.1 | 7 | | 1993 | 265.2 | 1 | | 1994 | 236.2 | 2 | | 1995 | 222.0 | 2 | | 1996 | 210.1 | 8 | | | Year | BF | Rank | | 1987 | 1059 | 3 | | 1988 | 1031 | 6 | | 1990 | 1014 | 7 | | 1991 | 1033 | 9 | | 1992 | 1026 | 3 | | 1993 | 1118 | 2 | | 1994 | 968 | 4 | | 1995 | 940 | 2 | | 1996 | 928 | 6 | | | Year | HRA | Rank | | 1993 | 31 | 8 | | 1997 | 34 | 8 | | | Year | BB | Rank | | 1986 | 127 | 2 | | 1987 | 110 | 1 | | 1988 | 120 | 2 | | 1989 | 106 | 10 | | 1990 | 100 | 8 | | 1991 | 104 | 4 | | | Year | K | Rank | | 1986 | 201 | 4 | | 1987 | 210 | 2 | | 1988 | 215 | 2 | | 1989 | 183 | 4 | | 1990 | 214 | 1 | | 1991 | 216 | 2 | | 1992 | 219 | 5 | | 1993 | 244 | 3 | | 1994 | 214 | 5 | | 1995 | 200 | 6 | |
| Year | WP | Rank | | 1985 | 7 | 7 | | 1986 | 13 | 2 | | 1987 | 11 | 5 | | 1988 | 17 | 1 | | 1989 | 9 | 10 | | 1990 | 17 | 1 | | 1991 | 12 | 5 | | 1992 | 15 | 2 | | 1993 | 11 | 8 | | 1995 | 11 | 5 | | | Year | ERA | Rank | | 1993 | 3.35 | 6 | | 1994 | 2.78 | 2 | | 1995 | 3.57 | 9 | | | | Year | K/BB | Rank | | 1992 | 2.31 | 9 | | 1993 | 2.77 | 7 | | 1994 | 2.74 | 9 | | | Year | RA/9 | Rank | | 1993 | 11.55 | 9 | | 1994 | 10.38 | 5 | |
| Year | HR/9 | Rank | | 1988 | 0.47 | 6 | | 1992 | 0.77 | 5 | | 1994 | 0.61 | 9 | | 1995 | 0.77 | 7 | | | Year | H/9 | Rank | | 1986 | 7.97 | 4 | | 1987 | 8.59 | 7 | | 1989 | 8.34 | 10 | | 1994 | 7.19 | 5 | | | Year | K/9 | Rank | | 1986 | 8.14 | 3 | | 1987 | 7.75 | 3 | | 1988 | 8.45 | 3 | | 1989 | 8.21 | 3 | | 1990 | 8.25 | 3 | | 1991 | 7.97 | 2 | | 1992 | 8.45 | 6 | | 1993 | 8.27 | 8 | | 1997 | 8.90 | 9 | | | Year | VORP | Rank | | 1993 | 59.3 | 5 | | 1994 | 68.9 | 2 | | | Year | QS | Rank | | 1991 | 20 | 9 | | 1992 | 19 | 9 | | 1993 | 27 | 1 | | 1994 | 22 | 5 | | 1995 | 22 | 2 | |
| Year | QSP | Rank | | 1993 | .730 | 1 | | 1994 | .667 | 5 | | 1995 | .667 | 5 | | | Year | CG | Rank | | 1987 | 7 | 1 | | 1988 | 4 | 8 | | 1991 | 7 | 2 | | 1992 | 6 | 6 | | 1994 | 4 | 2 | | 1995 | 2 | 9 | | | Year | CGP | Rank | | 1987 | .212 | 1 | | 1988 | .118 | 10 | | 1991 | .212 | 2 | | 1992 | .182 | 8 | | 1994 | .121 | 2 | | | Year | SHO | Rank | | 1987 | 2 | 1 | | 1989 | 1 | 7 | | 1992 | 2 | 2 | | 1994 | 2 | 1 | | 1995 | 1 | 4 | | 1996 | 0 | 9 | | | Year | GB% | Rank | | 1986 | 0.53 | 9 | | 1987 | 0.56 | 9 | | 1988 | 0.57 | 4 | | 1989 | 0.55 | 10 | | 1990 | 0.55 | 9 | | 1992 | 0.61 | 4 | | 1994 | 0.60 | 8 | | 1995 | 0.63 | 6 | | 1996 | 0.61 | 8 | | 1997 | 0.61 | 8 | |
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