With theretirement of Mike Hampton, this is a good time for a career profile and a look at how his career developed.
Mike Hampton was drafted in the sixth round in 1990 by the Seattle Mariners, from high school in Crystal River, Florida. He was a good athlete with a live arm and could have gone higher in the draft, but his stock was hurt by his 5-10, 180 pound size. He performed well in rookie ball, with a 2.66 ERA and a 59/40 K/BB in 64 innings for the Arizona League Mariners. His walk rate was high and he gave up 10 wild pitches, but arm strength was evident. I would likely give a similar pitcher a "Grade C with higher potential" nowadays.
The Mariners were impressed enough with Hampton that he started 1991 with High-A San Bernadino in the California League at age 18. He got hit hard, not surprisingly, with a 5.25 ERA and a 57/47 K/BB in 74 innings. Sent back to Bellingham in the Northwest League in July, he was more effective against age-appropriate competition, with a 1.58 ERA and a 65/26 K/BB in 57 innings. I'd likely rate a similar pitcher with a Grade C+ and maybe a sleeper alert tag nowadays.
Hampton returned to San Bernadino in 1992 and was terrific, going 13-8, 3.12 with a 132/66 K/BB in 170 innings, 163 hits. That's a big workload for a 19-year-old by modern standards, but he held up well and he was rated the Number Five prospect in the California League by Baseball America, scouts being quite impressed with the quality of his sinking fastball. I'd likely rate a similar prospect as a Grade B prospect now.
He began 1993 in Triple-A and posted a 3.71 ERA with a 84/33 K/BB in 87 innings. Promoted to Seattle, he got hit hard in 17 innings of work, with a 9.53 ERA and a 8/17 K/BB. I'd still likely have rated him a Grade B all things considered, with reports of above average sinking stuff and his youth. He was just rushed.
Hampton was traded to the Houston Astros in December '93, then opened '94 in the Houston pen, used as a LOOGY with decent results. He moved into the rotation in 1995 and remained in the rotation for the Astros, Mets, Rockies, and Braves for 10 years. As is well-known, he blew out his elbow in 2005 and suffered a variety of physical setbacks after that, until announcing his retirement this weekend.
All told, Hampton went 148-114 with a 4.06 ERA, ERA+ 107, 4.27 FIP in his career, spanning 2268 innings, with a 1387/901 K/BB, giving up 2370 hits. Career WAR was 31.1 His best year was 1999, when he went 22-4, 2.90 with a 155 ERA+ for the Astros. Peak WAR values were 5.1 in 1999, 4.4 in 2000, and 3.3 in 1997.
He was also a very good hitter for a pitcher, .246/.294/.356 in his career, including five seasons when he hit .291 or higher, with 16 homers in 725 at-bats. He won five Silver Slugger Awards.
Most Comparable Pitchers: Johnny Podres, Bruce Hurst, Barry Zito, Aaron Sele, Ron Darling, Kenny Rogers, Rube Walberg, Al Leiter, Tim Belcher, and Mike Flanagan. All very good pitchers, though short of greatness.
As a prospect, Hampton was noted by good performance at a young age against advanced competition. His K/IP ratios were never especially good, though as a ground ball type he could get away with that. He was rushed to the majors and had just a half-season of Double-A under his belt. He did serve an apprenticeship in the bullpen before being pushed into a full-time starting role.