William Edward Wagner (born July 25, 1971), nicknamed "Billy the Kid", is an American former professional baseball pitcher who played 16 seasons in Major League Baseball (MLB) for the Houston Astros, Philadelphia Phillies, New York Mets, Boston Red Sox, and Atlanta Braves from 1995 to 2010. A seven-time All-Star and the 1999 National League (NL) Rolaids Relief Man Award winner, Wagner is one of only eight major league relief pitchers to reach 400 career saves. A left-handed batter and thrower, Wagner stands 5 feet 10 inches (1.78 m) tall and weighs 180 pounds (82 kg).
A natural-born right-hander, Wagner learned to throw left-handed after fracturing his arm twice in his youth. Wagner's career 11.9 strikeouts per nine innings pitched (K/9) is the second highest of any major league pitcher with at least 900 innings pitched (Kenley Jansen). His career 2.31 earned run average, .187 batting average against, and 0.998 WHIP are the lowest of any left-handed pitcher in the live-ball era. He finished in the top ten in saves in the NL ten times, and in the top ten in games finished nine times. In 2025, Wagner was elected to the Baseball Hall of Fame.
Wagner was born to 16-year-old Yvonne and 18-year-old William “Hotrod” Wagner in Marion, Virginia, on July 25, 1971. Wagner's parents divorced in 1976 when he was five years old. Wagner and his younger sister, Chasity, spent the following 10 years living with various combinations of their parents, their stepparents, and their grandparents in the general Marion area. During this time, Wagner and his family often relied on food stamps. Wagner described a typical breakfast as a "few crackers with peanut butter and a glass of water."
At seven years old, Wagner's right arm was broken when, while playing football with some neighborhood kids, one of them accidentally fell on it. Shortly after having the cast removed, he broke the arm again. To avoid long-term damage to the arm, Wagner, a natural right-hander, began throwing a baseball left-handed.
At 14 years old, Wagner moved in with his aunt, uncle, and cousins, who lived in the Tannersville/Tazewell area about 25 miles (40 km) away from Marion. Despite having fallen behind a year in school due to the instability in his home life, Wagner was socially promoted to Tazewell High School because administrators feared he threw hard enough to injure his middle-school classmates.
Wagner graduated from Tazewell High School in Tazewell, Virginia, compiling a .451 batting average, 23 stolen bases, 29 runs batted in, 116 strikeouts in 46 innings, a 7–1 pitching record, and a 1.52 ERA in his senior season. As a senior in high school, Wagner was only 5 feet 5 inches (1.65 m) tall and 135 pounds (61 kg) and, as a result, could not get attention from Major League Baseball scouts or Division I schools.
Wagner chose to follow his cousin to Ferrum College, a small liberal arts college in Ferrum, Virginia, where they both played baseball and football. Coaches at Ferrum encouraged Wagner to focus on baseball, and he would eventually take their advice and stop playing football.
Wagner set single-season NCAA records for strikeouts per nine innings, with 19+1⁄3 in 1992, and the fewest hits allowed per nine innings, with 1.88. He was inducted into the Ferrum College Hall of Fame in 2003.
After the 1992 season, he played collegiate summer baseball with the Brewster Whitecaps of the Cape Cod Baseball League (CCBL), was named the league's outstanding pro prospect, and is a member of the CCBL Hall of Fame class of 2022.
Minor leagues and early major league career: 1993−97
Wagner was selected in the first round of the Major League Baseball draft in June 1993 by the Houston Astros. He pitched exclusively as a starting pitcher in Minor League Baseball for the Quad Cities River Bandits, until his major league debut. In 1994, Wagner led all North American minor league pitchers in strikeouts, with 204. Wagner made his first Major League appearance with the Astros, as a late-season promotion from AAA baseball, on September 12, 1995, pitching against one batter late in a 10–5 defeat by the New York Mets. This was his only opportunity to pitch for the Astros that season.
Wagner began in 1996, once again in the minor leagues as a starting pitcher, but he finished the season by becoming a relief pitcher for the Astros. He accumulated a 6–2 record with a 3.28 ERA, in twelve starts for the AAA Tucson Toros. His baseball contract was purchased by the Astros on June 2, 1996, and Wagner was then assigned exclusively as a short-relief pitcher by the Astros manager. He finished the Major League season with nine saves in 13 opportunities, allowed 28 hits, and he struck out 67 hitters in 51+2⁄3 innings – giving him a rate of 11.7 strikeouts per nine innings pitched. His opponents had a batting average of .165 against him.
In 1997, Wagner played his first full season in the major leagues. He accumulated 23 saves in 29 opportunities, and he struck out 106 batters in 66+1⁄3 innings. This set a major league record of 14.4 strikeouts per nine innings, which broke the old record of 14.1 set by the former Cincinnati Reds reliever Rob Dibble in 1992.
Wagner struck out the side 13 times in his 66 innings pitched, and his season total of 106 strikeouts set a Houston Astros record for relief pitchers.
In 1998, Wagner posted a 4–3 record with a 2.70 ERA and 97 strikeouts in 60 innings pitched. He saved 30 games, at the time the second-most in a single season in team history. He converted 19 consecutive save chances between his first blown save against the Los Angeles Dodgers, on April 12, and then his second one facing the St. Louis Cardinals on July 11.
On July 15, 1998, while protecting an 8–7 lead over the Arizona Diamondbacks, Wagner was struck by a batted ball on the left side of his head behind his ear. Wagner was alert and conscious on the ground, and his vital signs remained good. He was carried off the baseball diamond on a stretcher, and it was found that he had suffered a concussion. He spent the night in the hospital. On the next day, he flew home to Houston, and he was also immediately placed on baseball's 15-day disabled list. Wagner worked on his balance and coordination for weeks before he was cleared by the team physicians to embark on a rehabilitation assignment with a minor-league team. After pitching there in three games, Wagner was recalled to the Astros on August 6, and he completed the rest of the baseball season there without incident. The Astros won a franchise-best 102 games while winning the National League Central division title and leading the league in runs scored. Their season ended with a defeat at the hands of the San Diego Padres in the National League Division Series.
Wagner captured the 1999 Relief Man of the Year Award in the National League. He saved 39 games and struck out 124 in 74 innings (15 strikeouts per 9 innings). Wagner posted a 4–1 record with an ERA of 1.57 and had more saves than hits allowed (in 74+2⁄3 innings, he allowed 35 hits).
The 2000 season started off in typical fashion for Wagner, who saved three of the Astros' first four wins while retiring 16 of the first 20 batters he faced. However, after recording a save on May 4 against the Chicago Cubs, he suffered back-to-back blown saves on May 12–13 against the Reds. While he was still occasionally throwing 100 m.p.h. as measured by radar, he was not throwing his slider at 85–90 m.p.h. as often as he had been previously. Wagner continued to struggle before going on the disabled list with a torn flexor tendon in his pitching arm and would miss the final three and a half months of the season. He finished with a 2–4 record, a 6.18 ERA, and six saves in 15 opportunities, striking out 28 and walking 18 in 27+2⁄3 innings. He would rebound in 2001. Coming off elbow surgery, he posted a record of 2–5 with 39 saves in 41 chances and an ERA of 2.73. In 62+2⁄3 innings, he struck out 79 hitters.