Understanding the baseline rule can pay dividends on both sides of the ball. The Official Baseball Rules refer to the runner’s baseline as his base path under Rule 5.09 (b) (1). But I think there is a distinction between a base path and a baseline. When a runner is in a base path he has no restriction. When a runner has a baseline, he has restrictions as outlined below.

A Restricted Baseline

A runner only has a restricted baseline when he is avoiding a tag or is in a rundown. The tag attempt begins the moment the fielder in possession of the ball in hand or glove makes a motion toward the runner. At that moment, the umpire makes an imaginary line to the base the runner is advancing to, and the runner cannot exceed three feet to either side of the line. This means the runner has six feet of real estate to work with. Regarding the rundown, the baseline changes every time the runner changes direction.

Ruleball Considerations

• Offensively, if the runner is aware that a tag is imminent, he can widen his unrestricted base path before the fielder with the ball makes a motion toward the runner.
• This gives the runner more space to deal with and a better chance to avoid going out of the baseline.
• Defensively, the fielder who is making the tag attempt should make a motion toward the runner as soon as possible. It is at that moment that the baseline restriction begins.
• Baseline plays are not reviewable.

Runners Advancing to the Plate

The runner has a restricted baseline at all four bases only when he is avoiding a tag or is in a rundown. This includes home plate.

Play No. 1

The D’backs hosted the Mariners on June 9, 2025. In the bottom of the tenth, the D’backs had Ildemaro Vargas on third and Pavin Smith on first with one out when Alek Thomas hit a ground ball to Cole Young. The Mariners’ second baseman threw home to catcher Cal Raleigh, who attempted to tag Vargas.
Vargas evaded the tag but was called out for running out of the baseline by plate umpire Dan Iassogna.

Ruleball Comments

• Vargas had an unrestricted baseline as he attempted to reach the plate until Raleigh made a motion to tag him.
• Raleigh’s initial motion toward Vargas is what created the initial restricted baseline for Vargas. It was a straight line to the plate and Vargas was unable to exceed three feet to either side of the imaginary straight line.
• In my opinion, Iassogna made the proper call.
• When a runner is called out for running out of the baseline, the ball remains alive and there can be further play. Smith ended up on second base and Thomas on first base.

Play No. 2

The Brewers and Pirates played at PNC on May 23, 2025. In the bottom of the tenth with the score tied 5-5, Isiah Kiner-Falefa was at bat facing Abner Uribe with Alexander Canario on second base and Adam Frazier on first when Kiner-Falefa singled to right. Brewers’ right fielder Sal Frelick fired home to catcher William Contreras as Canario attempted to reach home.
Canario tried to go around Contreras but was called out by plate ump Mark Wegner for running out of the baseline.

Ruleball Comments

• The tag attempt was initiated the moment Contreras, with possession of the ball, made a motion toward Canario. At that moment Canario’s baseline was a straight line to the plate, and he was not allowed to exceed three feet to either side of the line.
• In Wegner’s judgment, Canario exceeded his restricted baseline and was called out.

Play No. 3

The Marlins hosted the A’s on May 3, 2025. In the top of the fifth inning, the A’s had Lawrence Butler on third and Brent Rooker on first and no outs when Tyler Soderstrom hit a bouncer back to pitcher Max Meyer. Butler broke for home and Meyer tossed to catcher Agustín Ramírez. Butler was now hung up in a rundown between third and home. Ramírez chased Butler toward third. The Marlins’ catcher then tossed to third baseman Connor Norby, who ran Butler back toward home.
Plate umpire Edwin Jimenez called Butler out for running out of the baseline. The ball remained live. Norby then fired to second baseman Javier Sanoja, who tagged Rooker for the double play. Soderstrom ended up on first base.

Ruleball Comments

• Jimenez properly called Butler out for running out of the baseline. Butler exceeded his restricted limit as Norby chased Butler toward home.
• As stated, the runner’s baseline changes every time he changes direction in a rundown.
• The ball remained alive when Butler was called out for running out of the baseline. Norby wisely threw to second baseman Javier Sanoja to nail Rooker and complete the 1-2-5-4 DP.
• In my opinion, Ramírez (the catcher) did not vacate properly in the rundown and could have been called for Type 1 obstruction if Butler got a piece of him when he changed course and headed home. I doubt that Ramírez was aware that Butler had six feet to deal with.

Play No. 4

Runner Attempts to Widen Base Path to Avoid Imminent Tag

The Guardians and Royals played in Kansas City on June 27, 2024. In the bottom of the fifth, the Royals had Nick Loftin on second base and Hunter Renfroe at bat with two outs when Renfroe hit a ground ball to José Ramírez at third base. Ramírez did not think he had a play at first, so instead of throwing the ball to first base, Ramírez attempted to tag Loftin, who was headed to third. Ramírez could not reach Loftin, but third base umpire Tripp Gibson called Loftin out for running out of the baseline.

Did Loftin run out of the baseline?

Royals’ manager Matt Quatraro didn’t think so. He argued the call and was ejected.

Ruleball Comments

• In my opinion, Loftin was wisely coached to widen his unrestricted base path in anticipation of the tag attempt by Ramírez.
• If you look at the video timer at the 6-second mark, that is when Ramírez makes a motion toward Loftin. At that point, you should freeze or pause your video and make your imaginary line like umpires do.
• From this corner, Loftin was within his restricted baseline at the point he made his approach to the base and never exceeded the three-foot limit. But that is a judgment call, as are all baseline calls.
• The worst thing a runner can do is wait until late in the play to avoid the tag and move horizontally to escape the tag. This plays into the three-foot rule, and the runner should be called out by the umpire.

Play No. 5

You Make the Call

The following play occurred in the July 1, 2024, game between the Brewers and Rockies at Coors Field. In the top of the fifth inning, Joey Ortiz was batting when he hit a tapper back to the mound. Rockies pitcher Austin Gomber chased Ortiz up the first base line.
First base ump Brian O’Nora called Ortiz out for running out of the baseline. Based on the information I have supplied in the above Ruleball Comments, would you have called Ortiz out for running out of the baseline? The call led to the ejection of Brewers manager Pat Murphy.

Ruleball Comments

• In my opinion, Ortiz did not exceed his three-foot lane from the time Gomber made a motion to tag him. It was, however, very close, and sometimes video distorts depth perception.
• Pause the video at the 3-second mark and judge if Ortiz exceeded his three-foot limit. I think Murphy had a good argument.
• Also, notice that the broadcasters were confused about the rule as they kept referencing the expanded runner’s lane, which has nothing to do with the baseline rule.
• The call proved pivotal as the Rockies won 8-7 in 10 innings.

Play No. 6

Runner Hurdles Over Defensive Player

The Rays hosted the Rangers on June 4, 2025. In the top of the first inning, Wyatt Langford, facing Shane Baz, hit a ground ball to Rays’ third baseman Junior Caminaro, who threw wide of first base. First baseman Jonathan Aranda, in his attempt to reach the ball, blocked Langford from touching the base. So, Langford hurdled over Aranda and was called safe by umpire Charlie Ramos. On the way back to first base, Langford was tagged by Aranda and called out.
Rangers’ manager Bruce Bochy challenged the out call, and it was reversed because Langford touched the base.

Ruleball Comments

• Was it legal for Langford to hurdle Aranda when avoiding the tag? Did Langford stay in the baseline? The answer to both questions is yes.
• There is a safety issue here, but under Pro and NCAA rules what Langford did was legal and he remained in the baseline.
• In this April 22, 2010, college game between Fordham and Iona, Fordham’s Brian Kownacki remained in his restricted baseline by leaping over Iona catcher James Beck to avoid the tag.

Play No. 7

Runners Make Use of Unrestricted Base Path

When a runner is running from first to second on a pick-off, the 3-3-6 or the 3-6, he should run at the target of the player who is receiving the ball. Watch this play that Boston’s Rajai Davis executed in the 2017 season. How often do teams practice this play defensively with a disruptive runner?

Play No. 8

Running Third to Home

If the runner is going on contact and the batted ball is hit toward third base, in my opinion, once the batted ball gets by the runner, he should get into fair territory. He has a non-restrictive runner’s path and should take advantage of what the rules allow. By getting between the third baseman and the catcher, he is creating a great deal of pressure for the thrower.

In a game between the Pirates and Cardinals on Sept. 18, 2020, the Cards’ Paul Goldschmidt legally hindered the throw from third baseman Ke’Bryan Hayes to the plate and scored. Again, how many teams practice this play with a disruptive runner?

Some teams coach runners to run in fair territory when advancing home on throws from third and the outfield. Again, a potential safety issue.

Rich Marazzi

Rules consultant/analyst: Angels, Dodgers, Mets, Nationals, Orioles, Padres, Phillies, Pirates, Red Sox, Rangers, Royals, Tigers, Twins, White Sox, Yankees, YES, and Chicago Sports Network