How rare is an inside-the-park grand slam home run? A home run is pretty simple. The batter hits the ball outside of the field, beyond the fence or wall.
An inside-the-park home run is when the batter is able to get around all the bases and score without hitting the ball outside the park.
A grand slam is when despite all the bases loaded, a batter hits a home run. While the home run is straightforward, a grand slam one inside the park is not simple.
A lot of things have to be lined up for that to happen, most of which are outside the batter’s control.
In this article, we will show just how rare they are, and explain why they have become so rare even though the number of home runs keeps rising.
How Rare is an Inside-the-Park Grand Slam?
In the history of professional baseball, since 1876, there have been 224 inside-the-park grand slams. That comes to just a little more than once per year. Ironically enough, there are more home runs hit than ever, but the inside-the-park homerun has become rarer in more recent times.
The Rare Event
How rare is an inside-the-park grand slam? Consider that since 1876 there have been 302 no-hitters pitched.
There have been 224 grand slams in the park in that time period, so it is even rarer than a no-hitter.
In the early days of baseball, the playing fields were less defined. There may not have even been a fence to show where the field ended.
This led to a lot more inside-the-park home runs because there were no outside-the-park.
Also, in the early days, the ball was not as bouncy as it is today. Before 1920 or so, it was called the “dead-ball era,” because the ball simply did not travel far.
Developments in making a baseball made it more lively, and that made it more possible to hit it a very long way.
Why the Inside-the-Park Grand Slam is so Rare
As stadiums became more defined, walls and fences were built, so the end of the playing field became more defined.
That led to fewer inside-the-park home runs. The possibility of going to bat with the bases loaded is also very low, making the feat even rarer.
Another obstacle to this feat is the error. An error occurs when a defensive player fails to make a play that he should have made. This is a judgment call.
So if an error occurs, and the batter manages to score off his hit, it will not go down as a home run.
It will go down as a single with an error. Considering that, there are probably more inside-the-park home runs than have been credited.
It is likely that there were more of these types of hits, but even so, they would still be rare. Especially in the early days, record keeping was inconsistent at best.
Often, the difference between an inside-the-park home run, and an error with a run scored, was the judgment of the one keeping score.
In the early 1900s, stadiums started being enclosed and walls were erected at the end of the outfield.
This meant a very well-hit ball would leave the park, so the inside-the-park homer became much rarer.
The inside-the-park homer depends on all the circumstances being right and that being a grand slam requires even more luck just to set up the possibility.
A more lively ball, and walls at the edge of the outfield, mean more balls go out of the park so the inside-the-park variety is less and less likely to happen.
The Modern Era
The last one recorded was in 2017, and the one before that was in 1999. Over 22 seasons there have been two, so the odds are very much against it.
To show how rare it has been in recent times, there were two in 1999, one in both 1997 and 1998, and there was one in 1991.
Inside the park home runs were much more common in the early days.
In 1909, for instance, Ty Cobb led the American League with nine home runs, and none were grand slams. They were all inside the park variety home runs though.
For three seasons, between 1911 and 1914, Frank Baker led the American League in home runs and he never had more than 12 in any of those seasons.
Most of his home runs, though, stayed inside the park. They did continue after the 1920s.
Jesse Burkett had 13 of them during his career, between 1976 and 1994.
There have been 87 inside-the-park grand slams since 1920. There were 137 before the 1920 season.
The heyday of this type of hit was between 1910 and 1914 when there were 33 over five seasons. The last 33 took 65 seasons, dating back to 1955.
The Home Run
Consider that in the first year of professional baseball, we had a total of 40 home runs for the entire season by the entire league.
It got even worse for a couple of years, with 24 the next year and 23 in 1878.
In 2021 there were 5,929 home runs recorded, and there have been two seasons since 2017 with more than 6,000.
The most in a season was in the 2019 season when 6,776 were hit.
The number of grand slams, inside or outside the park, has also increased dramatically. The first grand slam ever recorded was in 1881, and while there is no record, it is likely it was inside the park.
It was 1889 before more than 10 were hit, by the entire league. The number has grown along with the increase in home runs in general.
The most grand slams in a single season came in 2021 when 159 were hit. None of them were of the inside-the-park variety.
Frequently Asked Questions about How Rare an In-the-Park Grand Slam Is
Who had the most dramatic inside-the-park grand slam?
In 1966, Roberto Clemente hit a grand slam in the bottom of the ninth inning, which erased a three-run deficit and won the game for his team-the Pirates. Legend has it that his manager signaled for him to hold up at third. Clemente did not stop at third and went on to score the winning run.
What years had the most inside-the-park grand slams?
There were nine during both the 1910 and the 1911 seasons. There were eight in the 1914 season. There were seven in total, during the 1912 and 1913 seasons.
Why has the number of inside the park grand slams declined, while the total number of home runs has risen?
The main reason is the ball itself, which has changed over the years. Baseballs 100 years ago were made of material that did not bounce off the bat as much as they do today. Also, over the years, fields have become surrounded by walls or fences.
Conclusion on How Rare is an Inside-the-Park Grand Slam Home Run
Today it is not surprising to see at least one home run during a baseball game.
Your odds of seeing a grand slam are lower, and your odds of seeing a grand slam that stays inside the park are way lower than that.
Consider that there have been 100,690 home runs hit in the major leagues since 1999, and only two of them were inside-the-park grand slams.