MLB’s New Challenge System Changes the Game
If you’ve ever caught a baseball game—at any level—you probably recognize this scene: a pivotal moment in a tight contest. There’s a pitch grazing the corner of the strike zone, the umpire’s call is made, a player throws their hands up in frustration, and soon enough, the manager is out of the dugout, engaging in a passionate display. Meanwhile, fans in the stands are calling for a robot to take over the job.
Starting this season, Major League Baseball is set to alter that familiar scenario. With Opening Day on Wednesday, a fresh chapter in baseball begins. The Automated Ball-Strike Challenge System, or ABS for short, will allow some players to contest on-field calls during games.
The ABS system, provided by T-Mobile, keeps track of pitch locations in relation to a batter’s strike zone. Players can challenge a call on a ball or strike they believe to be incorrect. Once a challenge is made, a graphic will appear on the video board and during television broadcasts, akin to how tennis handles challenges.
After the umpire’s decision is either upheld or reversed, the game will carry on.
This may sound straightforward, but there are nuances involved. As we dive into the season, here’s what you need to know about MLB’s new ABS Challenge system.
Who Can Challenge the Pitch?
One interesting twist about the ABS Challenge system is that only batters, pitchers, and catchers can initiate challenges. Managers don’t have that privilege. The challenge needs to be made right away—no consulting the dugout or relying on video replays. For a challenge to count, the player must touch their hat or helmet.
Timing is, without a doubt, crucial. The instant requirement has led to situations like Cavan Biggio’s recent experience, where he believed he had drawn a walk but turned his bat over too soon—resulting in a denied challenge.
Moreover, since both pitchers and catchers can make these decisions, teams will use spring training to determine who is best positioned to opt for a challenge. Some teams are already hinting at relying on the catcher’s strategic spot during such instances.
How Many Challenges Does a Team Have?
In a standard nine-inning game, each team starts with two challenges. If a challenge fails, the team loses it; however, a successful challenge keeps their attempts intact. This has led to questions about strategy—teams want to be cautious and save challenges for high-stakes moments late in games.
If a game extends past nine innings, the losing team is given an additional challenge in the 10th inning. Should they utilize that and fail, they will earn another opportunity in the 11th, and the cycle continues into additional innings.
It’s worth noting, though, that if a team has a challenge left at the end of the 9th, they won’t receive another even if the game goes into extra innings, unless an inning starts without a challenge available.
How Does This System Operate?
Mechanically, the ABS system employs Hawkeye cameras strategically located around the field, using data from 12 different angles. This data is relayed on a per-pitch basis over a private T-Mobile 5G network. When a challenge occurs, a replay is shown on the stadium’s video board and during the television broadcast.
As for strike zone dimensions, MLB defines the strike zone’s width at 17 inches, matching the size of home plate. The upper limit of the zone is calculated at 53.5% of the batter’s height, while the bottom sits at 27%. The ABS system also assesses pitch locations relative to a strike zone that’s 8.5 feet deep in front of home plate—an important detail.
Interestingly, players are measured by an independent team during spring training to standardize heights. It’s vital since, well, humans can shrink throughout the day.
ABS System Data from Spring Training
According to MLB data, around 2.6% of pitches were challenged in spring training, with a turning-over rate of 52.2%. Notably, defensive players were more effective with a success rate of 54.4%, while batters succeeded exactly half the time.
It’s also interesting to see how challenge success changed over a game’s length. Early in the game—specifically the first three innings—the turnover rate was quite high at 60%, dropping to 51% in the middle innings, and further down to 42% by the eighth inning, finishing at 46% in the ninth.
Where Will ABS Systems Be Used?
The ABS Challenge system will be operational in all MLB ballparks, meaning it’s set to be a key feature in most games. However, three notable exceptions exist: the Mexico City Series, the Field of Dreams game, and the Little League Classic. Since these games occur outside regular MLB parks, the requisite Hawkeye cameras won’t be in place.
On the bright side, this system will still make a presence in the playoffs.
