The Infield Fly Rule Explained


Man Catching Baseball

One of the more challenging rules to understand in baseball is the infield fly rule. Most infield fly plays take around 8 seconds to complete, but because there is so much information to process in that short amount of time, the infield fly rule can seem like a mystery to most people.

What is the infield fly? In short, the infield fly is when the batter is called out on a short fly ball in order to protect the runners from an easy double play. For the infield fly rule to be in effect, there must be less than two outs and there must be runners on first and second or the bases must be loaded.

Sounds simple enough, but once you dive into the subject of an infield fly rule you’ll find that it’s quite complicated to understand (even for some Major League players).

Breaking Down the Infield Fly Rule

There are multiple components of the infield fly rule that an umpire needs to take into account. Remember, in a real game the umpire will have just a few quick seconds to factor in all of these different components and determine whether or not the play is ruled an infield fly.

The Infield Fly Rule Must Be a Fair Fly-Ball Hit Towards an Infielder

This is where the name “Infield Fly” comes from – a fly ball hit to where an infielder can catch the ball.

In order for a hit ball to be considered an infield fly, the ball must be a fly-ball, fair, and it must be hit in a place that an infielder can make an ordinary effort to catch the ball (source: page 149 of the official MLB rules).

An example of this would be when a batter hits a fly-ball in the vicinity of the shortstop and the shortstop is able to make an easy play on the fly ball.

What this rule also means, is that a fly-ball does not necessarily have to be hit in the infield. A fly-ball landing in the outfield grass, just beyond the infield, does not disqualify the play from being ruled an infield fly.

Remember, the purpose of the infield fly rule to prevent the defense from getting an easy double play or an easy triple play. So as long as an infielder is able to make an ordinary effort toward catching the ball, the batted ball can still be ruled an infield fly regardless of where the ball lands on the field.

Another thing the umpires must keep in mind is that the fly ball needs to be a fair ball. Sometimes, the fly ball can be hit down the first base or third base line, making it harder for the umpire to tell whether the ball is going to land fair or foul.

In the scenarios where umpires know the hit can be ruled an infield fly, but they are unsure if the ball is going to land fair or foul, the umpire will yell “Infield fly if fair!”

This means that if the defense ends up missing the fly-ball and the ball lands fair, the batter will still be out because the fair ball turned that call into an infield fly.

The Infield Fly Rule Must Have Less Than Two Outs

The second part of the infield fly rule to consider is that there are less than two outs.

Because the purpose of the infield fly is to prevent the defense from turning an easy double play or an easy triple play, it is impossible for the defense to get more than one out if there are already two outs in the inning. This means that the infield fly rule is not in effect when the offense has two outs.

So when a batter hits a fly ball in the infield, the umpire has just a few quick seconds to ask themselves how many outs there are in the inning. If there are no outs or one out, then one more item is checked off of their list for determining if the play should be ruled an infield fly.

The Infield Fly Rule Must Have Bases Loaded or Runners on First and Second

The next thing to consider is how many runners are on base. If there is just one runner on first base, then the defense is not very likely to turn a double play when there’s a fly ball hit in the infield.

So in order for the umpire to rule a play as an infield fly, the offense must either have runners on first and second base, or have the bases loaded.

The Infielder Uses Ordinary Effort on the Play During the Infield Fly Rule

This piece of the infield fly rule can sometimes be arbitrary, depending on the play.

A vast majority of the time a pop-up in the infield is a pretty easy play for the defense, but on occasion a ball can be hit a little outside of the infield where the infielder needs to run back a little for the ball.

This is where the infield fly rule can get a little tricky. The umpire must pay close attention to the play and determine whether or not the infielder is making an ordinary move towards catching the ball.

If the umpire sees the ball should be caught with ordinary effort, then the play is ruled an infield fly. If the umpire does not think the ball is getting caught with ordinary effort, then the play goes on like normal.

What Happens on an Infield Fly?

Umpire Calls for Infield Fly While Ball is in Flight

Once the umpire has determined the fly ball is an infield fly the umpire must call out “Infield Fly!” The umpire will be calling this out while the ball is still in flight – ideally, as soon as possible.

The earlier the infield fly rule is called, the more of a heads-up the base runners have. Once the baserunners hear that the play falls into the infield fly rule, they know that they can stay at their base and they don’t have to worry about running if the infielder doesn’t catch the ball.

Baserunners Can Advance at Their Own Risk During an Infield Fly

After the umpire has called “Infield Fly!”, the baserunners will need to be aware the ball is still live. Because the ball is still live during an infield fly, baserunners may advance to the next base at their own risk.

This means that if an error occurs by the defense during the play, runners are still able to advance to the next base.

Although it’s uncommon for a baserunner to advance to the next base during an infield fly, there can still be an opportunity to advance to the next base so baserunners always need to be prepared for that situation.

However, running at your own risk during an infield fly doesn’t always pay off. For a quick visual of runners advancing at their own risk during an infield fly, check out this video from the MLB.

Do Runners Have to Tag Up on an Infield Fly?

Since the batter is already called out while the ball is in mid-flight, a common question people have around the infield fly is if the runner still needs to tag up.

During an infield fly, baserunners need to tag up if the ball is caught by the infielder. Even though the batter has already been called out, the infielder can still catch the ball and force baserunners to tag up.

If the tag-up rule was not in effect during an infield fly, baserunners would have a tremendous advantage because they would be able to easily advance to the next base while the ball was in the air.

If the ball was hit extremely high towards an infielder and the tag-up rule was removed, could you imagine how many bases a runner could advance before the infielder even had the ball in their possession?

Because of how easy it would be for baserunners to advance to another base, the tag-up rule is still in effect during an infield fly.

Purpose of the Infield Fly Rule Is to Prevent Easy Outs

The main reason for having the infield fly rule is to prevent the defense from getting easy outs.

The way the infield fly rule works is that the batter is called out while the ball is in mid-flight and the runners are not forced to advance to the next base, but let’s go through a quick scenario around what would happen if the infield fly rule didn’t exist.

To set the scene, let’s start off with a common example of the scenario in which the infield fly rule would normally apply.

Imagine there are runners on first and second base and there is only one out in the inning. Now, the batter hits a high pop-fly to the shortstop.

If the infield fly rule didn’t exist, the shortstop would be able to intentionally drop the ball and force the runners on first base and second base to advance.

This means that the defense would be able to easily get a double play by having the shortstop intentionally miss the ball, throw the ball to third base for the force-out, then the third baseman would throw the ball to second for another force-out. And just like that, the inning would be over.

Thankfully, we have the infield fly rule to prevent the defense from getting easy outs like in the scenario described above.

If we took the same scenario above and applied the infield fly rule, the umpire would call “Infield Fly!” while the ball was still in the air on it’s way to the shortstop, which would indicate to the other players that the batter is out and the runners do not have to advance to the next base if the shortstop misses the ball.

In short, the infield fly rule exists in order to prevent the defense from getting easy outs. Without the infield fly rule in effect, defenses would be able to get easy double plays and potentially even get some triple plays.

Why No Infield Fly Rule With Runner on First?

As touched on in the previous section, the infield fly rule exists to prevent the defense from getting easy double plays. Once we understand the purpose of the infield fly rule we can also understand why the infield fly rule is not in effect when there is only a runner on first base.

Simply put, the infield fly rule does not apply when there is only one runner on first because the defense can not turn an easy double play.

When there is only a runner on first, the defense will be getting just one out if there is an easy pop-fly to the infield. The one out will come from the defense missing the fly-ball and getting the force-out at second base or the one out will come from the infield catching the ball.

There can be some exceptions to these scenarios – like if the batter decides to not run – but there is a high chance the defense will only be getting one out when there is a pop-fly to the infield. So the infield fly rule does not apply to the scenario where there is only a runner on first base.

Infield Fly Rule Examples

The best way I’ve found to fully understand something is by seeing lots of examples. So if you’re like me and you like seeing a lot of examples, check out this 5-minute video from Baseball Throne where they’ve mashed together multiple examples of the infield fly rule.

Infield Fly Rule During the Braves and Cardinals Game

A famous example of the infield fly rule surrounds a game played between the St. Louis Cardinals and the Atlanta Braves during the NL Wild Card game on October 5, 2012.

In one play during this important game, a fly ball was hit behind the shortstop’s head and the shortstop needed to run fairly deep into the outfield in order to make the catch.

While the shortstop was drifting closer and closer to the ball, the umpire called an infield fly, which meant that the batter was out.

Cardinal fans did not agree with the call and the game ended up being played under protest.

For a quick recap of the infield play during the Cardinals and Braves game, and for a great learning opportunity around the infield fly rule, check out this video of Harold Reynolds breaking down the play.

How to Score Infield Fly Rule

For those who are in charge of keeping score of the game, a common question around the infield fly rule is how exactly that should be written down in the scoring book.

To score the infield fly rule in the scorebook, simply markdown “IFR” for the batter and record that batter as an out. “IFR” stands for “Infield Fly Rule” in baseball.

Depending on the manager and how in-depth that manager wants to be, they may also want to know what position the batter hit the ball. If the manager wants to know the position the infield fly rule took place, then mark down the position number first, followed by “IFR”.

So, if the batter hit a fly ball to the shortstop and was called out due to the infield fly rule, you can score it as “6-IFR” in the scorebook.

Most of the time, just putting “IFR” in the scorebook is good enough, but always check with your manager to make sure the scorebook is scored in a way they can understand it.

Steve Nelson

I'm the owner of Baseball Training World. I live in Denver, Colorado and I enjoy playing baseball on two different adult baseball teams in the surrounding area.

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