SCOTTSDALE, Ariz. — Major League Baseball is changing … again.

Amid an era that has already seen significant alterations to the sport, most of which have been received favorably by fans and players alike, MLB will introduce perhaps its most dramatic change yet in 2026: the ability to challenge ball and strike calls.

For the past four seasons, MLB has invested heavily in testing the use of Automated Ball Strike (ABS) technology, predominantly at the Triple-A level but also during 2025 major-league spring training and the 2025 All-Star Game. At the minor-league level, early experimentation included the use of ABS to call all balls and strikes based on a designated virtual strike zone — crafted in space using 12 Hawk-Eye cameras placed around the perimeter of the field and tracking the pitch’s location, with the top and bottom boundaries of the zone determined by the batter’s height — with calls communicated to the home plate umpire via earpiece. But feedback on such a comprehensive system was less than positive among fans and players.

Instead, there was quickly a consensus among all parties that ABS would be better deployed in a limited capacity. Rather than completely eliminating the home plate umpire’s perspective, ABS — which offers a more black-and-white interpretation of the strike zone than a human ever could — could act as more of a support system than an overarching rule of law. Indeed, starting this season, no longer will MLB players have to begrudgingly accept a home plate umpire’s ruling no matter what; modern technology has provided the chance for recourse.

In September, the Joint Competition Committee — a group of six owners, four active players and one active umpire — voted to introduce the ABS challenge system for the 2026 season. On Thursday, at the conclusion of the annual Cactus League media day, former big-league pitcher and current vice president of on-field strategy for MLB Joe Martinez gave a presentation on how the ABS challenge system will function in 2026. It was similar to the one MLB gave a year ago ahead of its first round of testing in big-league spring training games, but this time, the stakes are considerably higher. This is no longer some early-stage experiment. This system is coming on Opening Day.

Welcome to a world in which players canargue balls and strikes — at least some of the time. In reintroducing the concept of the ABS challenge system, MLB stated its objective early and emphatically: “To provide players with an opportunity to correct missed calls in high-leverage moments in a manner that fans like.”

Here are the basics of how the ABS challenge system will work:

• Each team will have two challenges to begin each game, and all successful challenges will be retained. 

• Only the batter, catcher and pitcher are allowed to challenge a ball or strike call; protests from the bench or elsewhere on the field are prohibited, and umpires have the ability to deny a challenge if they believe it was aided or influenced by anyone else on field or in the dugout.

• To challenge a call, the pitcher, catcher or batter must tap his head immediately (in less than two seconds, roughly) to initiate a review. At that point, the umpire will announce the call is being challenged, and a graphic showing the ball’s location as determined by ABS will be displayed on the scoreboard and broadcast. The result of the challenge will be announced, and play continues. (In the past, even before ABS was a factor, there have sometimes been minor discrepancies between the strike zone displayed on the broadcast, the one embedded in MLB’s Gameday app and the one appearing on Baseball Savant’s Gamefeeds. MLB is working to ensure that all available forms of the strike zone are reflective of the zone being used by the ABS challenge system.)

• MLB defines the strike zone as “a two-dimensional rectangle that is set in the middle of home plate with the edges of the zone set to the width of home plate (17 inches) and the top and bottom adjusted based on each individual player’s height (53.5% of the batter’s height at the top and 27% at the bottom).” If any part of the ball is touching that strike zone — as tracked by the Hawk-Eye cameras — it is considered a strike. 

• Because the system is based entirely on player height, MLB has arranged for independent testers to measure all players during spring training using a standardized process to ensure that no player’s zone is too large or small based on a misreported height.

• If a game goes to extra innings, each team will be awarded one extra challenge each inning, but only if they do not have any remaining. For example, a team that has two challenges left after nine innings would not gain a third challenge for the 10th, but a team with zero challenges remaining after nine innings would regain one challenge for the 10th. This repeats with each successive extra inning.

• Challenges cannot be used if a position player is pitching.

On Thursday, MLB also supplied some data regarding how challenges came into play during spring training last year and another full season of testing in Triple-A. The overturn rate in Triple-A in 2025 was 50%, while the rate in spring training was 52%. Interestingly, catchers (56% overturn rate) were notably more successful at overturning calls than batters (50%) or pitchers (41%), lending credence to the possibility that some teams will institute strict guidelines regarding which of their players have the latitude to challenge calls. That’s just one of several strategic elements of the ABS challenge system that are still being contemplated by front offices, coaches and players in camp. 

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Another data point that could illuminate potential strategy is when during games the challenges have most commonly been deployed. In Triple-A, challenges were far more frequent in the later innings than the early innings, perhaps a reflection of a strategic preference to save challenges for more consequential or higher-leverage moments later in a game.

Conversely, in big-league spring training last year, the bulk of the challenges were used earlier in games, often in the first three-to-five innings. But as Martinez pointed out, that likely had less to do with a conscious strategy and more with who was playing earlier in those games: veterans testing the system before they exited to make way for the prospects and minor leaguers who often occupy the later innings of Cactus and Grapefruit League contests. This dynamic is crucial to keep in mind as we prepare for another spring with the ABS challenge system in action. 

Before we get to Opening Day, this spring will provide a larger sample of data for us to glean a preview of what’s to come. Last year, Hawk-Eye was installed in a select number of spring training ballparks, thus limiting certain teams’ exposure to the system; this time around, Hawk-Eye is in every spring training ballpark. But while teams are now preparing behind the scenes for how to take advantage of the challenge system in games that count, it’s unlikely that will meaningfully change their behavior — or that they’ll reveal such strategies — in exhibition contests.

Further complicating matters is the high percentage of players who will depart spring training early to participate in the World Baseball Classic — in which the ABS challenge system will not be used — and thus miss out on the reps with the system leading up to its official introduction in the regular season. 

All of this adds to the intrigue surrounding a new technology that will transform the sport in myriad ways we are still in the earliest stages of fully grasping. A spring training with widespread use of the ABS challenge system will serve as an appetizer to this new world we’re about to enter. 

But we won’t know the full scope until the real games commence at the end of March. Opening Day can’t get here soon enough. Let the head tapping begin.

Chris Paul officially ended his 21-season career as one of the NBA’s greatest point guards, announcing his retirement on Friday on Instagram.

“This is it! After 21 years I’m stepping away from basketball,” Paul wrote in the social-media post. “As I write this, it’s hard to really know what to feel, but for once — most people would be surprised — I don’t have the answer lol! But, mostly I’m filled with so much joy and gratitude!

“While this chapter of being an ‘NBA player’ is done, the game of basketball will forever be engrained in the DNA of my life.”

The fourth overall pick in the 2005 NBA Draft out of Wake Forest, Paul ranks second on the NBA’s all-time assist list — his 12,552 assists trail only John Stockton’s 15,806. He is also second behind Stockton in steals. He leaves as a 12-time All-Star, 11-time All-NBA point guard, five-time single-season assists leader, nine-time All-Defense selection and a member of the NBA’s 75th anniversary team.

For his career, Paul averaged 16.8 points, 9.2 assists and 4.4 rebounds. He was also a two-time Olympic gold medalist with the U.S. men’s national team. His next stop will be the Naismith Memorial Basketball Hall of Fame.

In a statement, NBA commissioner Adam Silver called Paul “one of the greatest point guards in NBA history and a true steward of our sport.” Silver also credited Paul for his role as president of the NBPA.

Paul and the Los Angeles Lakers’ LeBron James are the only players with at least 20,000 points and 10,000 assists in their careers. 

“Playing basketball for a living has been an unbelievable blessing that came with lots of responsibility,” Paul also said in his Instagram post. “I embraced it all. The good and the bad. As a lifelong learner, leadership is hard and is not for the weak. Some will like you and many people won’t. But the goal was always the goal, and my intentions were always sincere (Damn, I love competing!!)” 

Paul had previously announced this would be his final season, a farewell tour of sorts, after he signed with the Los Angeles Clippers in the offseason. The Clippers struggled to a 5-16 start and then sent him home from a roadtrip on Dec. 3, saying they planned to part ways with him after he reportedly clashed Clippers head coach Tyronn Lue and president of basketball operations Lawrence Frank.

The Clippers kept Paul on the roster until trading him to the Toronto Raptors at the trade deadline earlier this month. There was never an expectation Paul would play for the Raptors, and the team waived him on Friday shortly before his retirement announcement. 

The final game of Paul’s career was a 140-123 loss to the Miami Heat on Dec. 1 in which he had eight points and three assists in 14 minutes. He averaged a career-low 2.9 points, 3.3 assists and 1.8 rebounds in 16 games with the Clippers this season.

This was Paul’s second stint with the Clippers. He also played for the San Antonio Spurs, Golden State Warriors, Phoenix Suns, Oklahoma City Thunder and Houston Rockets after beginning his career with the New Orleans Hornets. 

Last season with the Spurs, Paul was the oldest player in NBA history to start all 82 games. It was only the second time in his career Paul played all 82. He finished his career having played in 1,370 regular-season games and 149 playoff games.

Despite Paul’s success and longevity, he never won an NBA championship. Untimely injuries sometimes limited his advancement in the playoffs, including in 2018 when he missed the last two games of the Western Conference finals as the Warriors beat his Rockets. He reached the NBA Finals for the first time in 2021 with the Suns and took a 2-0 lead over the Milwaukee Bucks only to lose the next four games.

Each week during the 2025-26 NBA season, we will take a deeper dive into some of the league’s biggest storylines in an attempt to determine whether trends are based more in fact or fiction moving forward.

Last week: The Thunder won the trade deadline

Fact or Fiction: The NBA’s response is enough to curb its tanking epidemic

The NBA’s tanking problem, it seems, creeps earlier and earlier into the season, to the point that two teams were fined on Thursday for violating the league’s tanking policies.

In consecutive games against the Orlando Magic and Miami Heat, the Utah Jazz removed Lauri Markkanen and Jaren Jackson Jr. prior to fourth quarters that were still in doubt and never reinserted either former All-Star into the contests. The Jazz blew a 17-point lead in the final 13:49 of a 120-117 loss to the Magic and actually held on to defeat the Heat 115-111.

Asked how close he came to subbing Markkanen and Jackson back in, Jazz coach Will Hardy said plainly, “I wasn’t,” blatantly baiting the league into taking action against them.

As Miami’s Bam Adebayo, whose Heat are vying for a play-in berth, conceded afterward, “We’ve got to find a way to win against teams that are, I guess you can say, trying to lose.”

So, there you had it: The Jazz were clearly undermining the integrity of the game, and an opposing player called them on it, which resulted in a $500,000 fine for Utah’s franchise.

“Overt behavior like this that prioritizes draft position over winning undermines the foundation of NBA competition and we will respond accordingly to any further actions that compromise the integrity of our games,” NBA commissioner Adam Silver said in Thursday’s press release. “Additionally, we are working with our competition committee and board of governors to implement further measures to root out this type of conduct.”

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The league’s board of governors plans to meet in March, when tanking will be a hot topic.

Jazz governor Ryan Smith is worth an estimated $2.6 billion, which means that $500,000 is about the same as $1 to someone who has $5,000 in his savings account. This is hardly a disincentive when the prize on the other end of their tank job — a high-end pick in what is considered a loaded draft — could increase the franchise’s value by hundreds of millions, if not billions, of dollars. Consider what Stephen Curry did for the Golden State Warriors.

As long as losing is the way to get the most ping-pong balls in the NBA’s annual draft lottery, teams that have no hope for the playoffs are going to intentionally lose games.

This is an epidemic. As much as a third of the league has every incentive to lose from here on out, especially the Jazz and Washington Wizards, who each owe their first-round picks to other teams if they do not fall in the bottom eight. The playoff fields in each conference are all but set — with two months to go in the regular season. There is little left to play for.

The season is too long, and there are financial reasons why team owners would not want to give up regular-season games — for the gate receipts. But what are they selling to fans? Stars are resting for all or parts of these games, and the product is, at best, watered down. At worst? Some of the product is essentially rigged, with one or both teams trying to lose.

Think a $100,00 fine against the Indiana Pacers for resting a healthy Pascal Siakam is going to dissuade Indiana from trying everything in its power to secure a top-three pick — and the rights to AJ Dybantsa, Darryn Peterson or Cameron Boozer — in the draft? Think again.

The Pacers are hoping and praying that Dybantsa, Peterson or Boozer, or whomever they get, eventually commands half a billion dollars in salary and is worth every penny to them.

If the NBA must fine teams, it must fine them ping-pong balls, hitting them where it counts in the lottery and removing the incentive to lose. Teams will learn real quick not to tank.

Maybe it is time to scrap the lottery entirely. Make it a wheel. Drastic measures are required to root out a serious problem. What the NBA does about gambling, salary cap circumvention and its All-Star Game are other matters, but this issue seems fixable.

As is, the Jazz assigned season-ending surgery to Jackson for a non-cancerous growth in his knee. Even though the procedure is necessary, Utah’s actions leave us to wonder if the team might have elected to postpone Jackson’s surgery if it had any incentive to win.

Likewise, the Wizards apparently traded for both Trae Young and Anthony Davis with the reported intention of resting both stars for the remainder of the season. What is the NBA going to do — convince Young that a lingering quad injury is no longer a concern? Tell Davis not to worry about the hand and groin injuries that he sustained on the Dallas Mavericks?

It is too easy for teams to find reasons to rest their stars in pursuit of losses. Anyone can have some sore soft tissue, and no amount of NBA investigation may discover otherwise.

So, what to do if you are the NBA? Incentivize winning, maybe. Give the No. 1 pick to the non-playoff team that wins the most games after the All-Star break, or something like that. This is hardly a revolutionary idea, and it would surely lead to more problems (for example, would not teams try to duck out of the play-in tournament?), but it is at least something.

And something is better than what we have now, which is a gamble — accepting the league’s fines in hopes of landing a franchise savior — that billionaires are willing to take.

Otherwise, fans will have to take the issue into their own hands and stop going to or tuning in to these games. Paying $1,000 for a family of four to see a game that may or may not feature its star players is, on the other hand, a gamble most fans may no longer make.

Determination: Fiction. Obviously.