Question: What MLB player is the Home Run record holder of Joyce Park?
Context: In baseball statistics, at bats per home run (AB/HR) is a way to measure how frequently a batter hits a home run.  It is determined by dividing the number of at bats by the number of home runs hit.  Mark McGwire possesses the MLB record for this statistic with a career ratio of 10.61 at bats per home run and Babe Ruth is second, with 11.76 at bats per home run.  Giancarlo Stanton, with 14.33 at bats per home run, currently holds the record among active players. The 2017 Major League Baseball Home Run Derby was a home run hitting contest between eight batters from Major League Baseball (MLB).  The derby was held on July 10, 2017, at Marlins Park in Miami, Florida, the site of the 2017 MLB All-Star Game.  On July 5, the participants that will be eligible to participate in the Home Run Derby were announced.  Aaron Judge won the Home Run Derby, becoming the first rookie to outright win the event. This is a list of some of the records relating to home runs hit in baseball games played in the Major Leagues.  Some Major League records are sufficiently notable to have their own page, for example the single-season home run record, the progression of the lifetime home run record, and the members of the 500 home run club.  A few other records are kept on separate pages, they are listed below. Joyce Park was a minor league baseball park in Keokuk, Iowa.  Joyce Park hosted Keokuk minor league teams in various seasons between 1929 and 1962.  The park had dimensions of (LF-CF-RF): 320-381-265 (1961) 306-385-345 (1962) and had a capacity of 3,500 (1962).  Notable Keokuk players of the Joyce park era included Home Run record holder Roger Maris and All-Star player and Baseball Announcer Tim McCarver. The 2016 Major League Baseball Home Run Derby (known through sponsorship as the T-Mobile Home Run Derby) was a home run hitting contest between eight batters from Major League Baseball (MLB).  The derby was held on July 11, 2016, at Petco Park in San Diego, California, the site of the 2016 MLB All-Star Game.  On July 8, the participants that will be eligible to participate in the Home Run Derby were announced.  Giancarlo Stanton won the Home Run Derby by defeating defending champion Todd Frazier 20-13. Roger Connor (July 1, 1857 – January 4, 1931) was a 19th-century Major League Baseball (MLB) player.  He played for several teams, but his longest tenure was in New York, where he was responsible for the New York Gothams becoming known as the Giants.  He was the player whom Babe Ruth succeeded as the all-time home run champion.  Connor hit 138 home runs during his 18-year career, and his career home run record stood for 23 years after his retirement in 1897. Walter Edward "Jiggs" Parrott (July 14, 1871April 14, 1898) was a professional baseball player whose career spanned eight seasons, four of which were spent with the Major League Baseball (MLB) Chicago Colts (1892–95).  Parrott, an infielder, compiled a career batting average of .235 with 174 runs scored, 309 hits, 35 doubles, 23 triples, six home runs and 152 runs batted in (RBIs) in 317 games played.  Although the majority of his career was spent in the major leagues, Parrott also played in minor league baseball.  He got his start playing amateur baseball with the East Portland Willamettes.  His professional baseball debut came in 1890 as a member of the Portland Webfeet.  Parrott was the first MLB player from Oregon.  He stood at 5 ft and weighed 160 lb .  His brother, Tom Parrott, was also an MLB player and a teammate of his on the Chicago Colts. Roger Eugene Maris (September 10, 1934 – December 14, 1985) was an American professional baseball player who played four seasons in the minor leagues and twelve seasons in the major leagues.  Maris played right field on four Major League Baseball (MLB) teams, from 1957 through 1968. The St. Louis Cardinals, a professional baseball franchise based in St. Louis, Missouri, compete in the National League (NL) of Major League Baseball (MLB).  Brewing magnate Gussie Busch's 37-year-long ownership of the club ended with his death in 1989, and his brewery, Anheuser-Busch (AB) took over.  In 1995, an investment group led by Drew Baur and William DeWitt, Jr., purchased the team and have owned the club since.  Shortstop Ozzie Smith – nicknamed "The Wizard" – collected a staggering array of defensive records and awards while performing acrobatic spectacles such as somersaults and flips that mesmerized Cardinal and non-Cardinal fans alike.  In 1998, Mark McGwire and the Chicago Cubs' Sammy Sosa collocated national attention with their chase of Roger Maris' single-season home run record of 61.  In addition, McGwire also set numerous team home run records.  For the 1990s, the Cardinals captured one division title and finished above .500 five times for a .488 winning percentage Jerry Schumacher is an American coach for the sport of track and field, specializing in distance running.  He has coached Olympic bronze medalist and the former American women's 10k record holder Shalane Flanagan, former Canadian 10k record holder Simon Bairu, the former men's American 10k record holder Chris Solinsky, the men's American two mile record holder Matt Tegenkamp, and the women's NCAA 10k record holder Lisa Koll.  Prior to 2008 he was the head coach of the University of Wisconsin–Madison track and field team.
Answer: Roger Maris