Cust attended Immaculata High School in Somerville, New Jersey. In 1997, he was first team High School All-American at first base.
Minor league careerEdit
In 1997, Cust was the first round draft pick (30th overall) of the Arizona Diamondbacks, and had a .447 on base percentage in 35 games in the Rookie League. Cust was a Pioneer League All-Star in 1998, where he led the league in walks (86), on base percentage (.530), and runs scored (75). In 1999 he led the California League in homers (32), on base percentage (.450), and slugging percentage (.651), and was Baseball America's 1st team Minor League All-Star DH, California League All-Star, and the Arizona Diamondbacks Minor League Player of the Year. In 2000 he had a .440 on base percentage at El Paso in the Texas League while leading the league in walks (117) and strikeouts (150). In 2001, he was a Pacific Coast League All-Star while leading the league with 102 walks, and in 2002 he was the Triple-A All-Star Game MVP. In 2006 he led the PCL with 143 walks, walking 24.5% of the time, while sporting a .467 on base percentage with 30 home runs.
In 11 minor league seasons with five different organizations, he hit exactly 200 home runs, had a .286 batting average, and a .429 on base percentage. Statistically, he hit a home run once every 19 at-bats, struck out once every 3 at-bats, and earned 1 walk per game. He led three different leagues in walks, two different leagues in on-base percentage, and two leagues in strikeouts.
In 2007, Oakland general manager Billy Beane said, "The thing is, when a guy hasn't gotten the opportunity, he acquires labels that are probably unfair as well. If you're in Triple-A long enough, it must mean you can't hit major-league pitching." 
Major League CareerEdit
On January 7, 2002 Cust was traded by the Diamondbacks with catcher J.D. Closser to the Colorado Rockies for pitcher Mike Myers. Cust spent the majority of the 2002 season with the Rockies Triple-A affiliate, the Colorado Springs Sky Sox. He played in 35 games with the big league club, going 11-65 (.169 batting average) with 1 home run. On March 11, 2003 he was traded by the Rockies to the Baltimore Orioles for outfielder Chris Richard and cash.
During an August 16, 2003 game, between the Baltimore Orioles and the New York Yankees, Cust was the tying run in the 12th inning with two outs when he tried to score from first base on a single to the gap by Larry Bigbie. Cust first stumbled and fell down between 3rd and home plate, resulting in his being caught in a rundown. Cust outmaneuvered the defense, and eventually found himself sprinting towards home plate with nobody covering it. Instead of scoring easily, however, Cust fell down for the second time in the same play. He was tagged out by third baseman Aaron Boone to end the game, providing one of the wildest endings to a baseball game in recent history. 
Cust finished the 2003 season batting .260 (19-73) with 4 home runs in the majors after being with the Ottawa Lynx (Orioles Triple-A team) for the first 4 months of the season. He would have just 1 one at bat in the majors with the Orioles in the 2004 season and was granted free agency after the end of the season.
On November 15, 2004 he was signed by the Oakland Athletics. He spent the whole season in Triple-A Sacramento and was granted free agency after the season. On December 6, 2005, he signed a minor league contract with the San Diego Padres. He just had 3 at bats in the 2006 season.
Cust began the 2007 with the San Diego Padres Triple-A team, the Portland Beavers. On May 3, 2007, the Padres traded Cust to the Oakland Athletics. The Athletics needed another designated hitter due to an injury to veteran Mike Piazza. He made his season debut on May 5, 2007, going 1-3 with a home run. Cust quickly endeared himself to A's fans by hitting 6 home runs in his first 7 games with the A's. Cust hit .346 with 14 RBIs during the seven game stretch. On May 13, 2007, with two outs and an 0-2 count in the bottom of the ninth, the A's rallied to score 5 runs to beat Joe Borowski and the Cleveland Indians 10-7, with Cust hitting a walk-off 3-run home run off Fernando Cabrera.
After hitting .348 with 1 double and 5 home runs along with 13 RBIs, Cust shared Co-American League Player of the Week honors along with teammate Dan Johnson for the week ending May 13, 2007. On August 10, 2007, Cust hit his first Major League grand slam off relief pitcher Macay McBride of the Detroit Tigers. He also hit a 3-run double earlier in the game to give him a career high 7 RBIs. He finished the 2007 season leading the Athletics in home runs with 26. In 2007, he walked 21.0% of the time, tops in the major leagues, and struck out 41.5% of the time, also tops in the majors.
On December 13, 2007, he was named in the Mitchell Report to the Commissioner of Baseball of an Independent Investigation Into the Illegal Use of Steroids and Other Performance Enhancing Substances by Players in Major League Baseball even though there was never proof/evidence to support the claim against him.
- Career statistics and player information from MLB, or ESPN, or Baseball-Reference, or Fangraphs, or The Baseball Cube
- Jack Cust Baseball Academy
- Cust says no to Mitchell Report A's DH denies using steroids