Semien grew up pitching and playing infield in El Cerrito Youth Baseball, across the bay from San Francisco, and was a member of the area's All-Star teams. He went on to attend St. Mary's College High School in Berkeley, California. At St. Mary's, he hit.471 as a junior,.371 as a senior, and was named all-league three times where he was drafted by the Chicago White Sox in the 34th round of the 2008 MLB draft. He chose not to sign and instead chose to attend college at the University of California, Berkeley. After struggling as a freshman, Semien improved as a sophomore, hitting.328. As a junior, Semien was the starting shortstop for the team, but hit.275, hurting his stock for the MLB Draft.
Professional career
Chicago White Sox
Semien was again drafted by the White Sox this time in the sixth round of the 2011 MLB draft. He started his career in 2011 with the Class AKannapolis Intimidators. He finished the 2011 season hitting.253 in 229 at-bats with, 15 2Bs, 2 3Bs, 3 HRs, 26 RBI and 3 SBs. Semien was moved up to Class A-AdvancedWinston-Salem Dash for the 2012 season. There he hit.273 in 418 at-bats with 31 2Bs, 5 3Bs, 14 HRs, 59 RBI and 11 SBs. For the 2013 season, Semien was ranked the White Sox #8 prospect. The White Sox selected Semien's contract from the Triple-A Charlotte Knights on September 3, 2013. He debuted against the New York Yankees on September 4, and recorded his first hit, a single, in his first at bat against CC Sabathia. He hit his first major league home run against J. A. Happ of the Toronto Blue Jays on September 23.
Oakland Athletics
After the 2014 season, the White Sox traded Semien, Chris Bassitt, Rangel Ravelo, and Josh Phegley to the Oakland Athletics in exchange for Jeff Samardzija and Michael Ynoa. He began the 2015 season as the A's starting shortstop. Semien struggled defensively throughout the season, committing a major-league-worst 35 errors, including a major-league-league-leading 18 throwing errors. He finished the 2015 season with a.257 AVG and 15 home runs and 11 stolen bases. After the season, the A's hired Ron Washington to work with Semien's defense. Semien showed improvement the following season, in 2016, committing only 21 errors. He led the major leagues in assists, with 477. He showed power at the plate, finishing second on the team in home runs with 27, as he batted.238 with 10 stolen bases. On April 17, 2017, Semien was placed on the 10-day disabled list due to a right wrist fracture, which also required surgery. For the 2017 season, he batted.249 with 10 home runs and 12 stolen bases. In 2018, he batted.255 with 15 home runs and 14 stolen bases. On defense he led the major leagues in assists, with 459. He was one of three finalists for a Gold Glove at shortstop in the American League, marking drastic defensive improvement from his previous seasons. In 2019, he batted.285/.369/.522 with 33 home runs, and led the major leagues with 747 plate appearances. His performance improvements garnered him even more attention from postseason awards voters as he was named to the inaugural All-MLB second team at shortstop, finished 3rd in voting for the American League MVP, and was again named one of three finalists for the Gold Glove.
Personal life
Semien's mother and father also attended the University of California, Berkeley, where Semien's father, Damien, played football. Semien and his wife, Tarah, have two sons; Isaiah, who was born in April 2017, and Joshua, who was born in May 2018.
