Tagging Up in Baseball: When a Runner Can Leave the Base
Tagging up in baseball under MLB rules: when a runner may leave on a caught fly, why foul flies count, and what happens to a runner who goes too early.
By CricketTaken EditorialPublished MLB Rules21 min read
- Runner may leave
- When a fielder first touches the ball
- Leaving early is
- An appeal play
- At-bats charged on a sacrifice fly
- 0
- Award if fielder falls out of play after a catch
- One base
A fly ball settles into the right fielder's glove about 300 feet from home plate. The runner on third has been standing with his left foot on the bag, watching the ball rather than the coach, and the moment leather meets ball he goes. Ninety feet later he slides across the plate ahead of the throw. One out, one run, and the batter walks back to the dugout without being charged an at-bat. That is tagging up, and it happens dozens of times a week in Major League Baseball.
The rule: when a fly ball is caught, every runner has to be touching his base at or after the instant a fielder first touches the ball before he may try to advance. Leaving before that instant is legal only in the sense that nothing happens unless the defense appeals; if it does, the runner is out. A runner who is off his base when the catch is made has to go back and retouch it before he can run, and if the ball or a tag gets to that base first, he is doubled off. Under the Official Baseball Rules, which govern MLB and its minor leagues, this applies to fair and foul flies alike.
Tagging up in baseball: the rule in one sentence
A runner's right to stay off his base disappears the moment a fly ball is caught. Before the catch, a runner on first can stand halfway to second, a runner on second can lead off toward third, and if the ball drops they are entitled to keep going. Once a catch is made, though, the batter is out, and every runner who was off his base is in the wrong place. He must retouch the base he started from before he can legally move up.
That retouch is the "tag." Players say a runner "tags" or "tags up" when he stands on the base waiting for the catch so he can leave as early as the rule allows. The word is the same one the rulebook uses for touching a base with the ball, which confuses young players, but the meaning is simply a touch.
| Batted ball | Must runners retouch before advancing? |
|---|---|
| Fair fly or line drive, caught | Yes |
| Foul fly, caught | Yes |
| Infield fly, caught | Yes |
| Infield fly, not caught | No, but the batter is still out |
| Fly ball dropped by the fielder | No; a dropped fly is not a catch |
| Foul tip caught by the catcher | No; it is a strike, not a fly ball |
| Ground ball | No; there is no catch to tag on |
The foul tip row confuses even regular viewers, because a foul tip is technically caught. It is a strike under the rules rather than a caught fly, and a runner stealing on the pitch keeps going. The page on the foul tip rule and how it differs from a foul ball explains why.
Two outs changes everything
With two outs, nobody tags up. A caught fly ends the inning, so there is nothing to tag up for, and a runner standing on his base would only be giving up a head start if the ball drops. Runners with two outs run on contact, all the way, on every fly ball. The tag-up decision is only made with nobody out or one out.
The runner is released by first touch, not by the finished catch
The definition of a catch in the rulebook ends with an instruction most fans never read. Runners may leave their bases the instant the first fielder touches the ball. Not when the fielder has the ball secured. Not when he has transferred it to his throwing hand. When the ball first meets the glove or the hand of a fielder, the runners are free.
The reason is the trick the rule was written to stop. If runners had to wait for a completed catch, an outfielder could catch a fly ball, bobble it deliberately into the air, catch it again, bobble it again, and walk it toward the infield while every runner stood on his base unable to move. Nobody would describe that as a fair contest. The rule removes the incentive by starting the clock at first contact.
What happens if the ball is juggled and then dropped
If the fielder touches the ball, bobbles it, and the ball eventually falls to the ground, there was no catch. The batter is a runner, a fair ball is in play, and the runners who stood on their bases waiting were never required to tag at all. They are now advancing on a live, uncaught fair ball. A runner who left at the first touch is fine either way.
When two fielders touch it
The release also applies when the ball is deflected from one fielder to another. A ball that pops off the center fielder's glove and is caught by the right fielder before it hits the ground is a legal catch, and the runners were released when the center fielder first touched it. The batter is out. Runners who left at the first touch, before the right fielder secured the ball, left legally.
This is one of the clearest cases in which the rulebook favors the offense. A fielder cannot freeze runners by being clumsy with the ball. If he touches it, they can go.
Caught off the base: doubled off and leaving too early
Two different situations get lumped together as "caught off the base," and the rulebook handles them differently.
Doubled off on a line drive
A runner on first takes a lead. The batter lines the ball hard at the second baseman, who catches it at chest height. The runner was moving toward second on contact and is now several steps off first with the ball already caught. He has to get back and retouch first. The second baseman throws to first, the first baseman catches it with his foot on the bag before the runner gets there, and the runner is out. A double play from one swing.
The umpire calls that out without any formal request from the defense. The throw to the base and the touch are themselves the act of putting the runner out, and the umpire is watching the base as the ball arrives. Either the runner retouched first or the base was touched with the ball first.
Leaving too early
A different runner, on third this time, leaves a split second before the right fielder touches a fly ball. He scores easily. The umpire does nothing. Leaving early is an appeal play: the umpire will not call it on his own, and the defense must ask.
To appeal, a fielder touches the base the runner left, with the ball in his possession, and makes it clear to the umpire that he is appealing. The appeal has to be made before the next pitch, before any play or attempted play, and, at the end of an inning, before the defensive team leaves the field. If the umpire agrees that the runner left before the first touch, he is out, and a run he scored on the play does not count. The page on appeal plays for missed bases and leaving early explains the procedure in full.
A runner who realizes he left too early can correct it by going back and retouching before the defense appeals. Once he does, he is treated like any other runner who tagged properly, and he may try again. In practice, by the time he has retreated, the chance to advance has usually gone.
Caught foul flies count, and why fielders sometimes let them drop
A caught foul ball is a legal catch. The batter is out, the ball stays in play, and every runner may tag up and advance at his own risk. Nothing in the tag-up rule distinguishes fair from foul.
That produces one of the strangest decisions in the sport. Bottom of the ninth, score tied, runner on third base and one out. The batter lifts a high foul ball down the right-field line. The right fielder drifts over toward the stands, gets under it, and lets it drop.
He is right to. If he catches it, the batter is out but the runner on third tags and very likely scores the winning run, because the right fielder is now off-balance near the wall in foul territory and nowhere near the plate. If he lets it fall, it is just a strike on the count, and the batter has to try again. A foul ball can never be worse than a strike for the defense, and in that spot a catch can lose the game.
When managers ask for the catch
The calculation reverses earlier in a game, or with a big lead, or when the runner on third is slow. An extra out may matter more than one run. The page on foul ball rules and the count has the rest of the rules for balls hit outside the lines.
The same logic applies at first and third base on pop-ups that drift into foul territory. A first baseman catching a pop-up near the stands with a runner on second has to remember that the runner can tag and go to third while he is turned the wrong way. Most professional fielders catch it and turn immediately to look. That reflex is drilled in spring training.
Tagging up from first and second, and on infield flies
Third base gets the attention because the payoff is a run. Tagging up from first and second is less frequent and in some ways harder to judge.
From second to third
A runner on second with fewer than two outs will tag on a fly ball to right field or deep center that he thinks he can beat to third. The right-fielder's throw to third is the longest throw an outfielder routinely makes, which is why runners from second tag on balls to right more readily than balls to left. A ball to the left fielder, who is much closer to third base, usually keeps the runner at second. The advance matters because a runner on third with one out can score on a fly ball, a ground ball, a wild pitch or a passed ball; on second he rarely scores on a fly.
From first to second
A runner on first tags up only on a very deep fly, usually to the warning track or the wall, when the outfielder is moving away from the infield as he catches it. Otherwise he goes halfway, so that if the ball drops he can reach second or third, and if it is caught he can get back. Tagging from first is uncommon enough that announcers mention it when it happens.
On infield pop-ups
Runners can tag on a caught infield pop-up too. It rarely makes sense because the catching fielder is a few feet from the base the runner wants, but a runner on third can sometimes score on a pop-up caught by a first baseman or catcher running away from the plate into foul territory.
What the infield fly rule changes
When an umpire declares an infield fly, with fewer than two outs and runners on first and second or the bases loaded, the batter is out at once. The ball is still live. If it is caught, runners must tag up just as on any other caught fly. If it falls untouched, they may run without retouching, at their own risk, and there is no force on any of them because the batter is already out. That second part is what defeats the exploit of letting a pop-up drop to turn a double play; the site's explainer on the infield fly rule walks through it.
The sacrifice fly: how a tag-up from third becomes a run
When a batter hits a fly ball that is caught by an outfielder, or by an infielder running into the outfield, with fewer than two outs, and a runner tags up from third and scores, the official scorer credits the batter with a sacrifice fly. That has three statistical effects, set out in the scoring rules.
- The batter is not charged with an at-bat, so the out does not lower his batting average.
- He is credited with a run batted in for the runner who scored, as he would be on a hit that drove in a run.
- The sacrifice fly does count in the denominator of on-base percentage, so it lowers that figure slightly.
The ball can be fair or foul. A caught foul fly that scores a runner from third is a sacrifice fly like any other.
- 0At-bats charged
- 1Runs batted in for the runner who scored
- 1Outs recorded on the catch
- 1Plate appearances counted
Credits to the batter under the Official Baseball Rules when a runner tags from third and scores on a caught fly with fewer than two outs.
What does not count as a sacrifice fly
The credit is only for a runner who scores. A runner who tags from second and reaches third on a fly ball has advanced, and that is valuable, but the batter receives no sacrifice credit for it and is charged with an at-bat. The scoring rule has worked this way since the sacrifice fly was reestablished as a separate statistic in 1954; earlier versions of the rule, in some seasons, gave credit for advancing runners to other bases.
There is one exception in the batter's favor. If the outfielder drops the ball and the runner scores, the scorer can still credit a sacrifice fly, provided he judges that the runner would have scored after the catch had it been made. The page on what earns a batter an RBI covers the related scoring decisions, and the effect on a hitter's on-base figure is explained in the guide to on-base percentage and what counts in it.
Time plays at the plate: when a doubled-off runner is the third out
One out, runners on first and third. The batter flies to center. The runner on third tags and runs home. The runner on first, who had gone too far on the hit, is caught off base and the center fielder's throw to first doubles him off for the third out. Does the run count?
It depends on timing, and that is why umpires call it a time play. A runner doubled off a base on a caught fly ball is not a force out. The rulebook's exceptions for third-out plays apply only to a force out, to the batter-runner retired before first, and to a preceding runner who failed to touch a base. A runner put out for failing to retouch is none of those, so the ordinary rule applies: if the runner from third crossed the plate before the third out was made at first, the run counts. If the throw beat him, it does not. The plate umpire is expected to note which came first and signal it. The comparison with force plays is set out on the page on force outs and tag outs.
The appeal that can take it back
The defense has one more card to play. If the runner from third left before the center fielder touched the ball, the defense can appeal against him after the third out, and the umpire can award an out on that appeal even though the inning is already over. The rulebook allows the defense to choose the out that is to its advantage, a so-called fourth out, which replaces the third. If the runner from third is ruled to have left early, the run he scored never counted.
The appeal must be made before the defense leaves the field. A catcher who knows the runner left early has to get the ball and touch third, or the opportunity is gone once the pitcher and all the infielders have left fair territory on their way to the dugout. The window is short.
| Third-out play after a runner scored on a tag-up | Does the run count? |
|---|---|
| Trail runner doubled off after the run scored | Yes |
| Trail runner doubled off before the run scored | No |
| Runner who scored is appealed for leaving early | No |
| Runner who scored is appealed for missing third or home | No |
No flying starts: the runner's footwork and timing
A runner may not take a running start from behind his base so as to be at full speed as he leaves it. The rulebook says so in a comment to its base-running rules: a runner who sets up behind his base, deeper than the bag in the direction away from the next base, and times his run to pass over the base at the moment of the catch, has not legally retouched. He is treated as leaving early, and the defense can appeal.
Without that rule, a runner on third with a deep fly to left could start from ten or twelve feet behind the bag in foul territory and be traveling at near top speed when he crossed it. It would be a much bigger advantage than any legal technique.
What runners do instead
The legal approach starts with the runner standing on the base. Most runners at third stand with a foot against the edge of the bag nearest home plate, body angled to see the outfielder, and lean their weight forward. Some face the outfield and turn; others rely on the third-base coach, who watches the catch and calls "go" the instant the fielder touches the ball. The coach's call takes longer to process than the runner's own eyes, so many professional runners watch the ball themselves on balls in front of them and listen for the coach on balls behind them.
The best tag-up runners lose almost nothing to the rule. They know the outfielder's footwork, so they leave as the glove closes rather than after. Umpires at third watch the runner's foot and the catch at the same time, which is part of why the umpire positions himself at an angle that keeps both in view.
When a catch carries the fielder out of play
An outfielder sprints toward the wall and makes a diving catch along the foul line, then tumbles over a low railing into the seats. The batter is out. The ball, however, is dead, and every runner is awarded one base.
The rulebook treats that as a special case because the fielder, by leaving the field of play with the ball, has taken the play away from the runners. They would have been entitled to tag and try to advance on the catch, and the fielder's momentum has denied them that chance. The one-base award is the substitute. It applies whether or not the runners had tagged up and regardless of how far off their bases they were, and it is the same award when a catcher or infielder catches a foul pop and falls into the dugout or the camera well.
The catch still counts as a catch, so the out is recorded. On a fly ball with a runner on third and one out, a fielder who catches it and falls into the stands has given up a run, since the runner on third is awarded home. Outfielders are taught to stay on their feet near low walls in that situation when they can, and catchers learn the same about the dugout steps. The ground-rule double page covers the other common out-of-play award, which sends runners two bases instead of one.
Why reaching in is different from falling in
The award depends on the fielder stepping or falling into the out-of-play area after making the catch. A fielder who reaches into the stands and makes a catch while staying on his feet on the field has made a legal catch, and the ball remains live. Runners must tag up and may advance at their own risk. The dugout has a stricter edge. A fielder may reach into it to make a catch, but he must have at least one foot on or over the playing surface, the lip of the dugout included, and neither foot on the ground inside. Plant a foot on the dugout floor and there is no catch at all, which means no out and nothing to tag up on.
Tag or go halfway: how runners and coaches decide
No two fly balls are the same, and the decision a runner makes in the half-second after contact is a judgment about the ball, the fielder and the game.
What the runner reads
- Depth. A fly ball to the warning track, with the outfielder running away from the infield, is the classic tag-up from third and often from second. A fly ball a few steps behind the infield dirt is not.
- The fielder's momentum. An outfielder who catches the ball while moving toward the infield has his weight going into the throw and gets more on it. One catching it while drifting back or sideways has to set his feet first.
- The arm. Runners and coaches carry scouting notes on every outfielder's arm. A runner who would score easily against one center fielder may hold against another on the same ball.
- The runner's own speed. A runner who is slow does not tag on a medium fly, whatever the arm.
What the game situation adds
| Situation | Typical decision on a medium-depth fly |
|---|---|
| No outs, runner on third, close game | Often holds; another chance to score with one out remains |
| One out, runner on third, close game | Tags and tries to score; this is the last good chance |
| Two outs, any runner | Runs on contact; no tag-up |
| Runner on first, ball not clearly deep | Goes halfway, ready to return or advance |
| Runner on second, ball to right field | Tags and tries for third more often than on a ball to left |
The score adds a second layer. A team trailing by several runs late in a game has less use for a single run from a risky tag than a team that needs exactly one. A team leading comfortably will take the out happily on a play at the plate and may concede the run to make sure of it.
How the defense answers
The fielding side has its own decisions to make on the same fly ball, and they start before the pitch. Outfielders shade in a step or two with a fast runner on third and fewer than two outs, accepting the risk of a ball over their heads to shorten the throw home. On the catch, the outfielder who has room will take a crow hop toward the plate, a skip that turns his body and adds force to the throw.
The throw itself goes through a cutoff man. On a tag from third, the first baseman or the pitcher usually stands in a line between the outfielder and the plate, and the catcher calls out whether to let the ball through or cut it. If the runner is going to score easily, the catcher yells "cut," the cutoff man catches the throw, and he looks for a trail runner who has tried to move up from first or second on the throw. That is how many tag-ups end with an extra base for nobody and an out at second instead.
The catcher's own position is the other variable. He has to take the throw in front of the plate or to the side of it and apply the tag. Since 2014 he may not block the runner's path without the ball, so on a close play he catches the throw and then swipes the tag across the runner's slide, rather than planting himself in the lane. The rule on home-plate collisions is covered with the other contact rules on the page about obstruction and interference.
Extra innings shifted the math in the regular season. Since MLB began placing a runner on second base at the start of each extra inning, a tag-up to third followed by a sacrifice fly has become a standard route for that runner to score. The site's piece on extra-innings rules and the automatic runner explains the format.
Checking a tag-up on replay
Whether a runner left his base before a fielder first touched the ball is a reviewable call under MLB's replay system. It is also an appeal play, and the order of operations matters.
- The catchA fielder catches a fly ball and a runner tags up and advances.
- Appeal on the fieldBefore the next pitch, the defense touches the runner's original base with the ball and appeals.
- Umpire rulesThe umpire watching the base calls the runner out or safe on the appeal.
- ChallengeEither manager may challenge that ruling, or the crew chief may request a review if the situation allows.
- Synchronized anglesReplay officials line up the frame of first touch with the frame of the runner's foot leaving the base.
- DecisionThe call stands unless the evidence is clear and convincing; runners are placed according to the result.
The usual sequence in MLB. The defense must appeal on the field first; replay reviews the umpire's ruling on that appeal, not the play by itself.
Why the appeal comes first
Leaving early is not called by the umpire on his own. If the defense does not appeal, there is no ruling to review, and a manager cannot challenge a call the umpire never made. A team that believes its opponents' runner left early has to complete the appeal on the field before the next pitch and then, if the umpire rules against it, challenge the ruling.
What the cameras show and do not show
The challenge for replay officials is that the two events happen in different places. The catch may be 350 feet from the base, and no single camera shows both the fielder's glove and the runner's foot. The replay center synchronizes separate feeds by time, finding the frame of first touch on one and the frame of the runner's foot leaving the bag on the other. The standard for overturning is clear and convincing evidence, and when the two feeds cannot be lined up to the frame, a close tag-up appeal is likely to end with the call on the field standing. The site's overview of MLB's replay review rules sets out the challenge limits and which other base-running calls are reviewable.
The NCAA and high school codes use the same basic tag-up rule, but they have their own replay arrangements, which vary by level and by event. The professional procedure described here is specific to MLB. For more on the rules this guide touches, the baseball section collects the rest.