Mark Williamson

Pitcher · Career Stats, Bio & Records (1987-1994)

Mark Williamson was a pitcher who played in Major League Baseball from 1987 to 1994 for the Baltimore Orioles, a span of 8 seasons. Across 365 career appearances, he went 46-35 with a 3.86 ERA, 397 strikeouts, and 21 saves. His career Pitcher PIV — Baseball Data Hub's era-adjusted measure of pitching impact — is 1777.9.

W (Wins):
Games credited to a pitcher whose team took a lead it never surrendered while he was the pitcher of record.
ERA (Earned Run Average):
Earned runs allowed per nine innings pitched: (ER × 9) ÷ IP. The primary measure of pitching effectiveness.
SO (Strikeouts):
For a batter, times retired on a third strike; for a pitcher, batters retired on a third strike.
WHIP (Walks and Hits per Inning Pitched):
Baserunners allowed per inning: (BB + H) ÷ IP. Under 1.00 is elite.

Data updated

W–L 46–35
ERA 3.86
WHIP 1.34
SO 397
Pitcher PIV 1777.9
Position
Pitcher
Bats / Throws
R / R
Height / Weight
6'0" / 155 lb
Born
7/21/1959 in Corpus Christi, TX, USA
MLB Debut
1987-04-08
Last Game
1994-08-04

Full name: Mark Alan Williamson

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Career Pitching Statistics

Mark Williamson — Career Pitching Statistics
W L G GS CG SHO SV IP H ER HR BB SO ERA Pitcher PIV
46 35 365 15 2 0 21 689.2 701 296 62 226 397 3.86 1777.9

Career ERA 3.86 vs. league average 3.98 across their career seasons — near league average.

Season-by-Season Pitching

Pitching Career Arc

Click a stat to plot it across every season.

Mark Williamson Stats, Bio & Career Records
Year Team Lg W L G GS CG SHO SV IP H ER BB SO ERA Lg ERA Pitcher PIV
1987 BAL AL 8 9 61 2 0 0 3 125.0 122 56 41 73 4.03 4.29 (+6%) 918.3
1988 BAL AL 5 8 37 10 2 0 2 117.2 125 64 40 69 4.90 3.73 (-31%) -1412.3
1989 BAL AL 10 5 65 0 0 0 9 107.1 105 35 30 55 2.93 3.71 (+21%) 1627.6
1990 BAL AL 8 2 49 0 0 0 1 85.1 65 21 28 60 2.21 3.86 (+43%) 556.0
1991 BAL AL 5 5 65 0 0 0 4 80.1 87 40 35 53 4.48 3.91 (-15%) -780.2
1992 BAL AL 0 0 12 0 0 0 1 18.2 16 2 10 14 0.96 3.75 (+74%) 74.4
1993 BAL AL 7 5 48 1 0 0 0 88.0 106 48 25 45 4.91 4.19 (-17%) 1420.2
1994 BAL AL 3 1 28 2 0 0 1 67.1 75 30 17 28 4.01 4.51 (+11%) -626.0
Career · 8 seasons 46 35 365 15 2 0 21 689.2 701 296 226 397 3.86 — 1,778

Lg columns show the league average for that season, with the player's figure as a percentage above or below it. Career totals the seasons listed above.

Career Batting Statistics

Mark Williamson — Career Batting Statistics
G AB R H 2B 3B HR RBI SB BB SO AVG OBP SLG OPS PIV
365 0 0 0 0 0 0 0 0 0 0 .000 .000 .000 .000 0

Season-by-Season Batting

Career Arc

Click a stat to plot it across every season.

Mark Williamson — Season-by-Season Batting
Year Team Lg G AB R H 2B 3B HR RBI SB BB SO AVG Lg AVG Lg OBP Lg SLG Lg OPS PIV
1987 BAL AL 61 0 0 0 0 0 0 0 0 0 0 .000 — — — — 0.0
1988 BAL AL 37 0 0 0 0 0 0 0 0 0 0 .000 — — — — 0.0
1989 BAL AL 65 0 0 0 0 0 0 0 0 0 0 .000 — — — — 0.0
1990 BAL AL 49 0 0 0 0 0 0 0 0 0 0 .000 — — — — 0.0
1991 BAL AL 65 0 0 0 0 0 0 0 0 0 0 .000 — — — — 0.0
1992 BAL AL 12 0 0 0 0 0 0 0 0 0 0 .000 — — — — 0.0
1993 BAL AL 48 0 0 0 0 0 0 0 0 0 0 .000 — — — — 0.0
1994 BAL AL 28 0 0 0 0 0 0 0 0 0 0 .000 — — — — 0.0
Career · 8 seasons 365 0 0 0 0 0 0 0 0 0 0 — — — — — 0

Lg columns show the league average for that season, with the player's figure as a percentage above or below it. Career totals the seasons listed above.

Game Log & Splits

View full game log (730 games) →

Per-game data from Retrosheet (regular season, through 2025).

Batting — Home / Away

Mark Williamson — Batting — Home / Away
SplitGABRHHRRBIAVG
Home18400000—
Away18100000—

Pitching — Home / Away

Mark Williamson — Pitching — Home / Away
SplitGIPHERBBSOERA
Home184356.23291261021823.18
Away181333.03721701242154.59

Last 10 Games — Pitching

Mark Williamson — Last 10 Games — Pitching
DateTmOppDecIPHRERBBSOHR
1994-08-04 BALMIL L 6.2944121
1994-07-30 BALTOR — 5.1733112
1994-07-26 BALCLE — 3.2322120
1994-07-23 BALOAK — 4.0200130
1994-07-18 BALSEA — 1.2211000
1994-07-09 BALOAK — 3.0400010
1994-07-03 BALLAA W 5.0311011
1994-06-30 BALCLE — 0.0211001
1994-06-28 BALCLE — 2.1422010
1994-06-22 BALMIL — 6.1511130

Fielding Statistics

Career Fielding Totals by Position

Mark Williamson — Career Fielding Totals by Position
Position G GS PO A E DP
P 365 15 75 76 7 4

Season-by-Season Fielding

Mark Williamson — Season-by-Season Fielding
Year Team Pos G GS PO A E DP
1987 BAL P 61 2 20 17 2 1
1988 BAL P 37 10 9 14 1 0
1989 BAL P 65 0 9 10 0 1
1990 BAL P 49 0 14 13 2 2
1991 BAL P 65 0 7 9 2 0
1992 BAL P 12 0 1 0 0 0
1993 BAL P 48 1 8 10 0 0
1994 BAL P 28 2 7 3 0 0

Career Games by Position

Position Diamond

Circle size = games played at each position.

Mark Williamson — Career Games by Position
Position Games
Pitcher 365

Salary History

Mark Williamson — Salary History
Year Team League Salary
1994 BAL AL $350,000
1993 BAL AL $500,000
1992 BAL AL $900,000
1991 BAL AL $685,000
1990 BAL AL $275,000
1989 BAL AL $120,000
1988 BAL AL $85,000
1987 BAL AL $62,500
Total Career Earnings $2,977,500

College History

Mark Williamson — College History
School Name City State Years Attended
Grossmont College El Cajon CA 1979, 1980
San Diego State University San Diego CA 1981, 1982

Most Similar Players

Career comps based on counting + rate stats and primary position. Score is relative — closest peer anchors at ~98%.

Career Spans

Mark Williamson (highlighted) compared to peers across the same era.

  1. 98
    Chuck Crim
    47-43, 3.83 ERA
  2. 95
    Keith Atherton
    33-41, 3.99 ERA
  3. 93
    Ricky Horton
    32-27, 3.76 ERA
  4. 92
    Les Lancaster
    41-28, 4.05 ERA
  5. 92
    Roy Lee Jackson
    28-34, 3.77 ERA
  6. 91
    Tom Gorman
    36-36, 3.77 ERA

Mark Williamson: the record in brief

Mark Williamson played a first major league game on April 8, 1987 and a last one on August 4, 1994. The team column never changes: it is the Baltimore Orioles from 1987 to 1994. Williamson played primarily as a pitcher and threw and hit right-handed. Born on July 21, 1959, in Corpus Christi, TX, USA, Williamson was listed at 155 pounds on a 6-foot-0 frame. The given name on file is Mark Alan Williamson.

Williamson pitched in 365 games, starting 15, and finished with a 46-35 record and 3.86 ERA. Williamson had 397 strikeouts and 21 saves. Williamson's 3.86 ERA was close to the 3.98 league figure for those seasons. 1989 brought Williamson a season-high 10 wins. The strikeout high was 73 in 1987. 1990 was Williamson's sharpest full season, a 2.21 ERA against the league's 3.86. Pitcher PIV, the site's era-adjusted run-prevention measure, totals 1,777.9 for Williamson's career.

Williamson appears at one position only: pitcher, in 365 games. On the mound, Williamson's fielding totals are 75 putouts, 76 assists and 7 errors.

Recorded salaries add up to $2,977,500, topping out at $900,000 in 1992. The college table lists Grossmont College in 1979 and 1980. Williamson's game-by-game log, linked below the splits, holds 730 games from Retrosheet.

The similarity section pairs Williamson most closely with Chuck Crim, Keith Atherton, and Ricky Horton.

Frequently Asked Questions about Mark Williamson

What years did Mark Williamson play?
Mark Williamson played in Major League Baseball from 1987 to 1994.
Was Mark Williamson a pitcher?
Yes. Mark Williamson pitched in the major leagues, recording 46 wins and 397 strikeouts.
What was Mark Williamson's career ERA?
Mark Williamson finished with a 3.86 career ERA, going 46-35 with 397 strikeouts.
How many strikeouts did Mark Williamson have?
Mark Williamson recorded 397 career strikeouts.
Is Mark Williamson in the Hall of Fame?
No. Mark Williamson has not been inducted into the National Baseball Hall of Fame.
What teams did Mark Williamson play for?
Mark Williamson played for the Baltimore Orioles.