What is HR in Baseball?
Home Runs · Batting
A home run (HR) occurs when a batter hits the ball over the outfield fence in fair territory, or hits an inside-the-park home run by running all four bases before being tagged out. The batter and all runners on base score. Home runs are the most dramatic and celebrated offensive event in baseball.
Formula
Home Runs are a counting stat — each qualifying hit over the fence is counted as 1 HR.
A grand slam (home run with bases loaded) counts as one home run for the batter but scores four runs. Home runs can be solo (no runners on base), two-run, three-run, or grand slams.
Benchmarks
| Level | HR |
|---|---|
| Legendary (season) | 50+ |
| Elite (season) | 40–49 |
| Excellent (season) | 30–39 |
| Above Average (season) | 20–29 |
| Average (season) | 10–19 |
ALL-TIME CAREER HR LEADERS
| Rank | Player | HR |
|---|---|---|
| 1 | Barry Bonds | 762 |
| 2 | Hank Aaron | 755 |
| 3 | Babe Ruth | 714 |
| 4 | Albert Pujols | 703 |
| 5 | Alex Rodriguez | 696 |
| 6 | Willie Mays | 660 |
| 7 | Ken Griffey | 630 |
| 8 | Jim Thome | 612 |
| 9 | Sammy Sosa | 609 |
| 10 | Frank Robinson | 586 |
BEST SINGLE-SEASON HR IN MLB HISTORY
| Rank | Player | Year | Team | HR |
|---|---|---|---|---|
| 1 | Barry Bonds | 2001 | SFG | 73 |
| 2 | Mark McGwire | 1998 | STL | 70 |
| 3 | Sammy Sosa | 1998 | CHC | 66 |
| 4 | Mark McGwire | 1999 | STL | 65 |
| 5 | Sammy Sosa | 2001 | CHC | 64 |
| 6 | Sammy Sosa | 1999 | CHC | 63 |
| 7 | Aaron Judge | 2022 | NYY | 62 |
| 8 | Roger Maris | 1961 | NYY | 61 |
| 9 | Cal Raleigh | 2025 | SEA | 60 |
| 10 | Babe Ruth | 1927 | NYY | 60 |
HISTORICAL CONTEXT
The home run was a rare event in baseball's early decades. Babe Ruth revolutionized the game in 1919–1920 when he began hitting towering fly balls out of the park with unprecedented regularity, transforming baseball from a contact-oriented game to a power game.
Ruth's single-season record of 60 home runs (1927) stood for 34 years until Roger Maris hit 61 in 1961 (over an expanded 162-game schedule). This record stood for 37 more years.
The 1998 home run chase between Mark McGwire and Sammy Sosa — both surpassing Maris's record — reinvigorated baseball's popularity. McGwire finished with 70, Sosa with 66. Barry Bonds then broke the record again in 2001 with 73, the current single-season record.
In the career home run race, Hank Aaron surpassed Babe Ruth's 714 career home runs in 1974, finishing with 755. Barry Bonds later surpassed Aaron, retiring with 762 career home runs — the all-time record.
ERA COMPARISON: HOW THE LEAGUE AVERAGE HAS SHIFTED
Home run rates have varied enormously across baseball history. The Dead Ball Era saw nearly none; the Steroid and Modern eras saw unprecedented power.
| Era | Years | Avg HR/Team/Season |
|---|---|---|
| Dead Ball Era | 1900–1919 | 25 |
| Live Ball Era | 1920–1941 | 78 |
| Post-WWII Era | 1942–1960 | 114 |
| Year of the Pitcher | 1961–1968 | 133 |
| Expansion Era | 1969–1988 | 127 |
| Steroid Era | 1989–2005 | 162 |
| Post-Steroid Era | 2006–2019 | 172 |
| Modern Era | 2020–2024 | 189 |
Figures represent average home runs hit per team per 162-game season. Computed from Lahman historical MLB data.
FREQUENTLY ASKED QUESTIONS
What is HR in baseball?
A home run (HR) occurs when a batter hits the ball over the outfield fence in fair territory, or hits an inside-the-park home run by running all four bases before being tagged out. The batter and all runners on base score. Home runs are the most dramatic and celebrated offensive event in baseball.
How is HR calculated?
Home runs are a simple counting statistic — each home run a player hits is recorded. Career totals accumulate over a player's entire major league career. Home runs come in two forms: over-the-fence (the vast majority) and inside-the-park home runs.
What is a good HR in baseball?
In the modern era, hitting 30+ home runs in a season is considered excellent for a position player, 40+ is elite, and 50+ is legendary. The league leader typically hits 45–55 home runs per season. Home run rates vary significantly by era — the Deadball Era saw very few, while the Steroid Era featured many 50+ HR seasons.
Who hit the most home runs in MLB history?
Barry Bonds holds the all-time career home run record with 762, followed by Hank Aaron (755) and Babe Ruth (714). Alex Rodriguez (696), Jim Thome (612), and Willie Mays (660) are also among the top career home run leaders.
What is the single-season home run record?
Barry Bonds set the single-season record with 73 home runs in 2001. Mark McGwire (70 in 1998, 65 in 1999), Sammy Sosa (66, 64, and 63 in three separate seasons), and Roger Maris (61 in 1961) are the only other players to surpass 60 home runs in a season.
EXPLORE MORE STATS
Pitching
ERA
Learn more →
Batting
OPS
Learn more →
Batting
AVG
Learn more →
Batting
RBI
Learn more →
Advanced
WAR
Learn more →
Pitching
WHIP
Learn more →
Batting
SLG
Learn more →
Batting
OBP
Learn more →
Pitching
Wins
Learn more →
Pitching
SO
Learn more →
Batting
SB
Learn more →
Pitching
SV
Learn more →
Batting
BB
Learn more →
Advanced
FIP
Learn more →
Pitching
K/9
Learn more →
Pitching
BB/9
Learn more →
Advanced
BABIP
Learn more →
Advanced
wOBA
Learn more →
Advanced
PIV
Learn more →