Mark Williamson career ERA
3.86Career Regular Season
Mark Williamson has a career ERA of 3.86 over 8 regular seasons.
| GP: Games the player appeared in, however briefly. | W: Games in which this pitcher was credited with the win. | L: Games in which this pitcher was charged with the loss. | ERA: Earned runs allowed per nine innings pitched — lower is better. Under 3.00 is excellent. | IP: Innings pitched. The decimal counts outs, so 6.2 is six innings and two more outs. | K: Batters this pitcher struck out. | BB: Times the batter reached first base on four balls. | WHIP: Walks and hits allowed per inning pitched — lower is better. Around 1.00 is elite. | SV: Games finished by protecting a narrow lead to the last out. | ||
|---|---|---|---|---|---|---|---|---|---|---|
| 1987 |  BAL | 61 | 8 | 9 | 4.03 | 125.0 | 73 | 41 | 1.30 | 3 |
| 1988 | BAL | 37 | 5 | 8 | 4.90 | 117.2 | 69 | 40 | 1.40 | 2 |
| 1989 | BAL | 65 | 10 | 5 | 2.93 | 107.1 | 55 | 30 | 1.26 | 9 |
| 1990 | BAL | 49 | 8 | 2 | 2.21 | 85.1 | 60 | 28 | 1.09 | 1 |
| 1991 | BAL | 65 | 5 | 5 | 4.48 | 80.1 | 53 | 35 | 1.52 | 4 |
| 1992 | BAL | 12 | 0 | 0 | 0.96 | 18.2 | 14 | 10 | 1.39 | 1 |
| 1993 | BAL | 48 | 7 | 5 | 4.91 | 88.0 | 45 | 25 | 1.49 | 0 |
| 1994 | BAL | 28 | 3 | 1 | 4.01 | 67.1 | 28 | 17 | 1.37 | 1 |
What the columns mean: W · L · ERA · IP · K · BB · WHIP · SV
- Best season on file: 0.96 in 1992.
- Most recent: 4.01 in 1994.
Average of 8 regular seasons, 1987 through 1994. Figures come from ESPN's box scores and were last read on November 2, 2026.