You know how MLB’s new ABS challenge system has placed a sharper focus on ball-strike calls in 2026? Each team begins with two challenges, and only the pitcher, catcher or batter can call for one immediately after a ruling. Teams retain successful challenges, allowing incorrect calls to be corrected in roughly 15 seconds. The system was put to the test Friday night when Alan Porter worked behind the plate for the San Francisco Giants’ game against the Arizona Diamondbacks.

He officiated the 2025 World Series Game 5 between the Toronto Blue Jays and the Los Angeles Dodgers and achieved 97% accuracy. He called 155 of 159 pitches correctly. However, his accuracy record went for a toss on Friday as he made one blown call after another. While the Automated Ball-Strike system saved the day for both the San Francisco Giants and the Arizona Diamondbacks, Porter made a record that’s hard to ignore amid the growing calls against the umpires.

“Umpire Alan Porter called the worst game of the day. He missed 21 calls in the Giants-Diamondbacks game, including 18 in the first 5 innings. He had 9 calls overturned — tied for the 2nd most this season,” Umpire Auditor shared via X.

Yes, 21 missed calls on Friday! This was followed by heated exchanges and ejections. However, despite having nine calls overturned, first place still belongs to Clint Vondrak, who had 11 of 16 challenges overturned in a June 8 game between the Milwaukee Brewers and Athletics. Still, with nine overturned calls, the ABS was kept busy the entire time on Friday.

“In all honesty, it just hasn’t been a good night for Alan Porter,” NBC’s broadcaster Duane Kuiper said.

The night started well for Porter as the first two innings went without any trouble. However, the third inning proved not to be so kind to Porter.

The pivotal sequence began with one out and nobody on in the third inning. Porter ruled a pitch to Arizona’s Lars Nootbaar a ball, though it appeared to catch enough of the zone for strike three. Giants catcher Andrew Knizner did not challenge the call, allowing Nootbaar to remain at the plate.

Nootbaar made San Francisco pay for the missed opportunity, lining a double to center field. Corbin Carroll followed with a two-run homer off Blade Tidwell, putting Arizona ahead 3-2. The Diamondbacks went on to score five times in the inning and built a 6-2 lead, turning what could have been the inning’s second out into the start of a decisive rally.

That sequence brought the limitations of MLB’s ABS challenge system to the forefront. While it later corrected several of Porter’s ball-strike calls, the Giants did not challenge the pitch to Nootbaar, leaving the original ruling in place. The subsequent challenges involving Geraldo Perdomo and Nolan Arenado only added to the scrutiny on Porter’s strike zone.

The drama unfolded when the D-backs’ Geraldo Perdomo entered the batter’s box. The first pitch from Blade Tidwell was initially called a ball, only to be challenged. The call was overturned, and just then another challenge followed, this time with Nolan Arenado in the batter’s box. Porter called a ball, which was overturned.

As a result, Arenado eventually doubled, which had irked the Giants manager, Tony Vitello. He screamed from the Giants’ dugout for a foul call and got ejected.

Arenado eventually doubled, which sparked more controversy around Porter. Arenado’s double was down the line. Between innings, San Francisco manager Tony Vitello yelled from the dugout that Arenado’s hit should have been called foul. While the call was not Porter’s, he ejected Vitello from the game. Third-base umpire Alex MacKay ruled that Arenado’s ball bounded over the third-base bag, making it a fair double.

However, the Giants’ dugout strongly believed the ball traveled wide of the bag in foul territory. Because it was a judgment call, the play was non-reviewable. After Vitello got ejected for arguing the call, Logan Webb ran to the far end of the rail near third base to defend his manager. Second-base umpire Roberto Ortiz then officially ejected Webb from the dugout.

On the other hand, Porter’s errors continued. The D-Backs successfully went on to challenge balls on Shay Whitcomb, Osleivis Basabe, and Bryce Eldridge. In comparison, the Giants had successful calls on Corbin Carroll and Arenado, as well as a strike on Drew Cavanaugh.

Nevertheless, not all of Porter’s calls got overturned. There were a total of 4 calls made correctly by Porter. Both the Giants and the Diamondbacks unsuccessfully reviewed two each.

Apart from Porter, Friday was not kind enough for another MLB umpire in Chicago.

MLB umpires had an overall bad day on Friday

While Alan Porter had a tough day, Bill Miller was close enough. During the Cubs-Reds game on Friday, Miller had a ridiculous eight ball-strike calls overturned. Yes, that’s just behind Porter.

Then there was Edwin Moscoso, who officiated the Boston Red Sox-New York Yankees game on Friday. Seven of his calls reportedly got overturned.

While there’s no denying the challenges in umpiring in MLB, so many error calls on a single day spark concern. The ABS may have saved the day, but without it, the game’s momentum could have been altered.

“These umpires have a really, really, really difficult job,” Reds’ Sal Stewart told The Athletic at the All-Star Game. “I only have to know my zone; they need to know the whole league’s zone. … I just want to say, man, the umpires have done a great job. This system, it’s not easy. They have to know a lot of people, different heights.”

For the fans and players, the ABS proved to be a relief, while pushing the umpires towards more mockery and fans’ wrath. Still, the ABS is certainly here to stay. What MLB needs to think about is making their umpiring more accurate.