Sig Mejdal

Sig Mejdal (pronounced My-Dell; born December 31, 1965) is an American assistant manager, and sabermetrics analyst for the Baltimore Orioles and a former NASA engineer. He previously helped the St. Louis Cardinals make draft picks. Mejdal turned his personal interest in baseball into a career after being inspired by Moneyball in 2003.

Sig Mejdal
Sig headshot.png
Sig Mejdal
Born (1965-12-31) December 31, 1965 (age 55)
San Jose, California, U.S.
Alma materUniversity of California, Davis; San Jose State University


Sig Mejdal grew up in San Jose, California. His mother was a nurse and his father was a career army officer. In his youth, Mejdal played little league baseball for six years.[1]: 43  He was a fan of the Oakland A's and a member of the Society for American Baseball Research.[2] According to UC Davis magazine, Sig Mejdal was "fascinated with the stats on the backs of baseball cards."[3] Mejdal graduated from University of California, Davis with bachelor's degrees in mechanical engineering and aeronautical engineering. He later earned master's degrees in operations research and cognitive psychology[4] from San Jose State University.[5] While attending college in the late 1980s, he worked as a blackjack dealer at High Sierra in Lake Tahoe.[4]

After graduating from UC Davis in 1989,[3] Mejdal worked for Lockheed Martin's satellite operations unit at the Onizuka Air Force Station.[1]: 113 [6] Mejdal's interest in baseball was recreational until 2003, when Moneyball inspired him to consider pursuing a career in sabermetrics.[3][7] He attended the Winter Meetings in search for a job in baseball,[8] but ended up working for NASA as a biomathematician in the Fatigue Countermeasures Group.[1]: 23  Mejdal studied sleep patterns of astronauts on the International Space Station[9] in order to optimize their sleep schedules.[8][10]

While working for NASA, Mejdal had a side job as the chief quantitative analyst for Sam Walker's fantasy baseball team Streetwalkers Baseball Club,[10][11] which was participating in the Tout Wars competition's "Battle of the Experts."[10] The fantasy team would later become the subject of Walker's book: Fantasyland: A Sportswriter's Obsessive Bid to Win the World's Most Ruthless Fantasy Baseball.[9]

In 2005, Sig Mejdal was recruited to do sabermetrics for the St. Louis Cardinals' new analytics department.[12] He took 22 months of data from college baseball games and ran it through an algorithm to determine the likely performance and stats baseball players would achieve.[13] According to Sports Illustrated, "[o]ver the next seven seasons the Cardinals would draft more players who became big leaguers than any other organization."[4] He was promoted to senior quantitative analyst in 2008[14] and director of amateur draft analysis in January 2011.[15][16] Mejdal created a formula to predict the risk of injury to baseball players[17] and contributed a section on injury probability to The Bill James Handbook.[18]

In 2012, Mejdal became the Director of Decision Sciences for the Houston Astros, where he supported recruitment decisions based on physical tests and historical player performance.[2][7][19] Hiring Mejdal to apply an analytics-based decision tree on their player choices was part of the effort to revitalize the team and address performance issues in prior seasons.[4] He helped the team create the STOUT system, named after the combination of "stat" and "scout," for making player choices.[20] The system was criticized for de-humanizing players, but after trading off some players and making new recruits, the Astro's farm system became ranked among the best in baseball.[4] The Astros also used analytics to persuade players that were uncomfortable with non-traditional positions on the field to embrace shifts, which the team now uses very heavily.[4][21]

In 2015, Mejdal was one of the team's advisers whose login credentials were believed to have been used to hack into the team's database.[22]

When Mike Elias was hired from the Astros as general manager of the Baltimore Orioles, Elias hired Mejdal as his assistant general manager.[23]


  • Mejdal, Sig; Melissa M. Mallis; Tammy T. Nguyen; David F. Dinges (March 2004). "Summary of the Key Features of Seven Biomathematical Models of Human Fatigue and Performance". Aviation, Space, and Environmental Medicine. 75 (3): 4–14. PMID 15018262.

Further readingEdit


  1. ^ a b c Sam Walker (27 February 2007). Fantasyland: A Sportswriter's Obsessive Bid to Win the World's Most Ruthless Fantasy Baseball League. Penguin Books. ISBN 978-0-14-303843-6. Retrieved 13 January 2013.
  2. ^ a b McTaggart, Brian (January 31, 2012). "Analyze this: Astros' Mejdal takes on unique role". Retrieved December 14, 2012.
  3. ^ a b c "A numbers game". UC Davis Magazine. pp. Volume 28, Number 2, Winter 2011. Retrieved December 14, 2012.
  4. ^ a b c d e f Reiter, Ben. "Astro-Matic Baseball". SportsIllustrated. Retrieved June 27, 2014.
  5. ^ Dorsey, David (April 17, 2006). "Teams turn to numbers crunchers". The News Press. pp. CC.1. Retrieved December 14, 2012.
  6. ^ Matthews, Alan (October 2, 2006). "BA's Alan Matthews attends the Major League Scouting Bureau's "Scout School"". School's In. Baseball America. Retrieved December 14, 2012.
  7. ^ a b Cohen, Jason (January 5, 2012). "Astros GM Makes Up a Fancy Title for His "Moneyball" Stat Guy". Daily Post. Archived from the original on January 15, 2012. Retrieved December 14, 2012.
  8. ^ a b Booher, Kary (April 23, 2008). "Cards turn analytical for draft decisions". News-Leader. Retrieved December 14, 2012.
  9. ^ a b Levine, Zachary (February 11, 2012). "Astros' Sig Mejdal to utilize diamond data in projection game". Houston Chronicle. Retrieved December 14, 2012.
  10. ^ a b c Walker, Sam. "Reality Check". Sports Illustrated. Retrieved December 14, 2012.
  11. ^ Walker, Sam (June 15, 2006). "A Different Kind of Draft Day". The Wall Street Journal. Retrieved December 14, 2012.
  12. ^ Walton, Brian (January 13, 2012). "Interview: Cards Scout Head Kantrovitz: Pt. 1". Retrieved December 14, 2012.
  13. ^ Enterprises, Lee (July 3, 2015). "Analytics at heart of Cards' success, federal probe : Sports". Retrieved July 12, 2015.
  14. ^ Everson, Darren (March 7, 2008). "Baseball Taps Wisdom of Fans". The Wall Street Journal. Retrieved December 14, 2012.
  15. ^ "Cards Promote Two in Baseball Ops". CBS. January 7, 2011. Retrieved December 14, 2012.
  16. ^ Carroll, Will. "Cardinals Team Healthy Report 2011". Sports Illustrated.
  17. ^ Carroll, Will (March 4, 2008). "Team Health Reports". Baseball Prospectus.
  18. ^ Carroll, Will (April 11, 2006). "Under The Knife: Danger is Will's Middle Name". Baseball Prospectus. Retrieved December 14, 2012.
  19. ^ Rogers, Phil (January 7, 2012), "Time for Big Z to step to plate", Chicago Tribune, retrieved December 14, 2012
  20. ^ Goold, Derrick (June 7, 2007). "Baseball Draft: Cardinals get STOUT". St. Louis Post-Dispatch.
  21. ^ Waldstein, David (May 12, 2014). "Who's on Third? In Baseball's Shifting Defenses, Maybe Nobody". New York Times. Retrieved June 27, 2014.
  22. ^ Schupak, Amanda (June 24, 2015). "What the Houston Astros hack can teach you about cybersecurity". CBS News. Retrieved July 12, 2015.
  23. ^