MLB test of robot umpires for checked swing calls moving up to Triple-A

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MLB test of robot umpires for checked swing calls moving up to Triple-A

2026-03-17 01:32 Last Updated At：01:41

MIAMI (AP) — Major League Baseball's experiment of a robot umpire technology system allowing challenges to checked swing calls is moving up from Class A to Triple-A.

MLB will also test moving second base slightly to position it entirely within the infield, which would reduce by 9 inches the distance between first and second, and between second and third, according to a memorandum sent to teams last week.

It will try out reducing permissible disengagements by pitchers from two to one per plate appearance and stricter limits on batter timeouts and resetting the pitch clock for issues with PitchCom, the electronic signaling device that has been used since 2023.

There will also be a test allowing starting pitchers to re-enter games in the lowest level of the minor leagues. It's not expected this test will lead to MLB implementation, but it's being considered for the minors to improve development and player health by allowing more flexible workload management.

MLB's Automated Ball-Strike Challenge System, the so-called robot umpire, launches when the season starts March 25 following tests that started in the minors in 2019. A batter, catcher or pitcher can appeal a ball/strike call by the human umpire under a system in which each team has two challenges and keeps its challenge if successful. Additional challenges become available to teams in extra innings.

An experiment began last May 20 in the Class A Florida State League allowing challenges to checked swing calls, and the test was extended to the Arizona Fall League.

Starting on May 5, the checked swing test will take expand to the Triple-A Pacific Coast League in additional to the FSL.

“The batter, pitcher or catcher may also appeal the umpire’s decision regarding whether the batter swung at a pitch,” according to the memo from MLB vice president of on-field strategy Joe Martinez to general managers and other club executives. “A swing will be considered to have occurred if the maximum angle between the bat head and the bat handle exceeds 45 degrees.”

Martinez said the strikeout rate was cut by 3% during last year's testing.

In addition, umpires at games in the Triple-A International League will be instructed to apply the 45-degree threshold for determining swings starting May 5. The Official Baseball Rules do not specify a standard for checked swings, stating only: “A strike is a legal pitch when so called by the umpire, which is struck at by the batter and is missed.”

Since 1976, the rules have said: “The manager or the catcher may request the plate umpire to ask his partner for help on a half swing when the plate umpire calls the pitch a ball, but not when the pitch is called a strike.”

Starting pitchers will be allowed to re-enter a game after being removed at the Arizona Complex League, Florida Complex League and Dominican Summer League. A removed starting pitcher is eligible to return if he threw at least 25 pitches during the inning he was removed, can return only at the start of an inning and may re-enter only once.

MLB enlarged bases to 18-inch squares from 15 in 2023, a change the led to more stolen bases because of a decreased distance of 4 1/2 inches between first and second, and second and third.

Second base has been centered on the exact spot of second, but the experiment in the International League will place it “entirely within the perimeter of the infield diamond during the second half” of the season.

Citing an increase in the average time of a nine-inning game from 2 hours, 36 minutes in 2024 to 2:38 last year and a decrease in stole base attempt success rate from 80.2% in 2023 to 77.8% last year, MLB will experiment with changes to pitch clock rules.

Teams at Triple-A will be assessed a mound visit if play is stopped for a PitchCom problem, and if a team is out of visits an automatic ball will be charged.

At all levels, the clock will not stop when a catcher leaves the catcher's box to give defensive signals, and players other than the pitcher and coaches must leave the mound before the clock on mound visits runs out. A violation would result in an automatic ball.

At High A, batters will not be allowed to request time if the bases are empty and in Class A no timeouts will be allowed. Exceptions will be allowed for brush backs, possible injuries or equipment problems.

Allowed disengagements by pitchers from the rubber will be lowered from two to one at Double-A.

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Winds, blizzards and triple-digit heat put over half of the US in the path of extreme weather

WASHINGTON (AP) — Chaotic weather coast to coast in the U.S. — from surprising heat in California to damaging winds around Washington, D.C. — put more than half the American public in the path of extreme conditions Monday.

Storms across the nation's eastern half forced airlines to cancel more than 3,000 flights nationwide Monday, and many schools closed early in the mid-Atlantic states where high winds and tornadoes were in the forecast.

Blizzards buried parts of Michigan, Wisconsin and Minnesota while torrential rains flooded homes and washed out roads in Hawaii.

In Washington, the House of Representatives postponed votes because of difficulty traveling with inclement weather, and federal agencies told workers to go home early.

Airport delays and cancellations piled up Monday in some of the nation’s largest airports — including those in New York, Chicago and Atlanta.

The private weather service AccuWeather calculated that more than 200 million people were under threat Monday of some kind of dangerous weather.

Those range from extreme heat and wildfire advisories to flood and freeze watches from the National Weather Service.

The storm system that dropped snow by the foot in the Midwest is barreling toward the East Coast with dangerously high winds and potential for “producing strong and long track tornadoes,” the weather service warned Monday.

“Wind is the primary threat, but within any of these areas of strong wind there could be some embedded tornadoes and even the potential for a tornado to develop ahead of the line,” said Evan Bentley, a meteorologist with the weather service.

The biggest threat stretched from Maryland to the upper edge of South Carolina.

North Carolina Gov. Josh Stein urged residents to enable emergency alerts on their phones ahead of expected wind gusts topping 70 mph (112 kph).

Beyond the threat to lives and property, “whether it’s wind gusts from a squall line, blizzard or snow, or just wind because of the storm, you’re looking at several major airports being impacted,“ said AccuWeather senior meteorologist Tyler Roys.

Blizzard conditions persisted Monday in parts of Wisconsin and Michigan, where the storm brought as much as 2 feet (61 centimeters) of snow by morning.

Another round of snow and gusty winds on Monday could come close to doubling those totals in upper Michigan.

The thousands of flights canceled nationwide Monday included more than 400 in and out of Chicago O’Hare International and another 300 at Atlanta’s Hartsfield-Jackson International, according to FlightAware, which tracks flight disruptions.

Kelly Price, who was trying to get home to Colorado after a family vacation in Orlando, Florida, said their Sunday night flight wasn’t canceled until the early Monday morning.

“By that time the only place for us to sleep was the airport floor. So we’re all tired and frustrated,” she said, adding that the soonest flight they could book doesn’t leave until Tuesday afternoon.

A heat dome over the Southwest will push temperatures well into the triple digits in Arizona most of the week, much earlier than the region usually sees.

Much of California is starting to feel like summer too. The San Francisco Bay Area and Sacramento will see temperatures pushing toward 90 F (32 C) by midweek.

“This is a heat wave that we have not seen before in recorded history in the Southwest,” said AccuWeather meteorologist Dan DePodwin.

Phoenix is expected to have five straight days of triple digit temperatures this week — only once before, in 1988, has the city recorded a 100 F (37.8 C) day in March, DePodwin said.

Unrelenting rains triggered landslides and flooded homes and farmland in Hawaii over the weekend.

Some areas of Maui received more than 20 inches (51 centimeters) of rain, Maui County Mayor Richard Bissen said in a social media post.

Resident and real estate broker Jesse Wald, who recorded video of a coastal road’s collapse, said parts of the road were flooded by mud and sediment.

“In the 20 years I’ve been here I’ve never seen this much rain,” he said.

Forecasters said the East Coast storms were expected leave sharply colder weather in its wake.

By Tuesday morning, wind chills below freezing were expected to reach the Gulf Coast and the Florida Panhandle with warnings in effect across the Southeast and in part of Arkansas, Oklahoma, Louisiana, and Texas, forecasters warned.

To the north, rain was expected to change over to snow behind the cold front with heavy snow possible in the central Appalachians of West Virginia.

Brumfield reported from Cockeysville, Maryland, and Seewer from Toledo, Ohio. Associated Press writers Margery Beck in Omaha, Nebraska; Julie Walker in New York; Jeff Martin in Atlanta; Gary Fields in Washington; and Sophia Tareen in Chicago contributed.