The following is a list of records for a game, season, or career that were broken in each Major League Baseball season by players, teams, or others. This does not include dates when additional stats were recorded by the same player above one's own record set (unless broken by someone else in between) or records by a team that do not lead the majors. Some of the records were subsequently broken by others:
1897 July 12: Most inside-the-park home runs in a game – 3 by Tom McCreery
1919
Most home runs, season – 29 by Babe Ruth.
1920 July 19: Most home runs, season – 30 by Babe Ruth; ended the season with 54. Highest slugging percentage, season – .847 by Ruth.
1921 July 18: Most career home runs – 139 by Babe Ruth; ended his career in 1935 with 714. Ruth's passing of Roger Connor for the career home-run record was not recognized at the time. Connor's career total of 138 was not accurately documented until the 1970s; at one time, he was thought to have hit only 131. September 15: Most home runs, season – 55 by Ruth; ended the season with 59.
1927
September 27: Most RBI, season – 172 by Lou Gehrig; ended season with 175. September 30: Most home runs, season – 60 by Babe Ruth.
1930 September 17: Most RBI, season – 176 by Hack Wilson; ended season with 191.
1932 July 10: Most hits in a game by a batter – 9 by Johnny Burnett
1941 July 2: Longest hitting streak in a single season – 45 by Joe DiMaggio; extended to 56. July 5: Longest hitting streak spanning one or more seasons – 46 by Joe DiMaggio; extended to 56.
1961 October 1: Most home runs, season – 61 by Roger Maris
1974 April 8: Most career home runs – 715 by Hank Aaron; ended his career in 1976 with 755.
1985 September 8: Most career hits – 4,190 by Pete Rose; ended his career in 1986 with 4,256.
1987 August 14: Most home runs by a rookie, season – 39 by Mark McGwire; later extended to 49.
1991 May 1: Most career stolen bases – 939 by Rickey Henderson; ended his career in 2003 with 1,406.
1995 September 6: Most consecutive games played – 2,131 by Cal Ripken Jr.; later extended to 2,632 in 1998.
1997 September 4
9: Most teams with which a player has hit 20 home runs in a season – 2 by Mark McGwire
1998
June 25: Most home runs in a calendar month – 19 by Sammy Sosa (extended to 20 on June 30). September 8: Most home runs, season – 62 by Mark McGwire; later extended to 70. Sosa also broke the 37-year-old record held by Roger Maris and was briefly the sole record-holder, hitting his 66th home run of the season (which would be his final total) before McGwire did.
1999 April 23: Most grand slams hit in one inning – 2 by Fernando Tatís Most grand slams surrendered in one inning – 2 by Chan Ho Park
2001 October 4: Most career runs – 2,246 by Rickey Henderson; ended his career in 2003 with 2,295 October 5: Most home runs, season – 71 by Barry Bonds (hit #72 in same game; finished season with 73) Highest slugging percentage, season – .863 by Bonds.
2002 April 30: Most franchises against which a pitcher has earned a win: 30 by Al Leiter Highest on-base percentage, season – .582 by Barry Bonds.
2003 September 17: Most extra-base hits, season, by a team – 608 by Boston Red Sox
2004 July 10: Most intentional walks, season – 68 by Barry Bonds; broke his own record; finished season with 120 October 6: Most hits in one season – 262 by Ichiro Suzuki Highest on-base percentage, season – .609 by Bonds.
2005 June 8: Youngest player to reach 400 home run mark – Alex Rodriguez, age
2006 April 28: Most consecutive games with a home run by a right-handed hitter – 7 by Kevin Mench April 29: Most home runs in the month of April – 14 by Albert Pujols
2007 August 4: Youngest player to reach 500 career home runs – Alex Rodriguez, age August 7: Most home runs, career – 756 by Barry Bonds; later extended to 762
2008
April 2: Most consecutive games without an error for a first baseman – 194 by Kevin Youkilis; later extended to 238 games May 9: Most baserunners picked off, career – 92 Kenny Rogers May 16: Most consecutive starts with a no-decision – 9 by Shawn Chacón
2009 June 17: Most games caught – 2,227 by Iván Rodríguez; later extended to 2,427 games.
2010 August 4: Youngest player to reach 600 career home runs – Alex Rodriguez, age
2011 August 2: Most games hitting home runs from both sides of the plate in a career – 12 by Mark Teixeira September 19: Most career saves – 602 by Mariano Rivera; later extended to 652 saves.
2012 April 17: Oldest pitcher to win a game – Jamie Moyer, age . Extended record on May 16 (see below). May 16: Oldest player to drive in a run – Moyer, age June 23: Most walk-off home runs – 13 by Jim Thome
2013 September 20: Most career grand slams – 24 by Alex Rodriguez; later extended to 25.
2015 October 21: Most consecutive postseason games with a home run – 6 by Daniel Murphy
2017 September 25: Most home runs by a rookie, season – 50 by Aaron Judge; later extended to 52.
2019 September 28: Most home runs by a rookie, season – 53 by Pete Alonso
References