MLB Tests First-Ever Checked-Swing Challenge System In Arizona Fall League
Image credit: AFL checked-swing replay on the video board at Salt River Fields (Photo by Bill Mitchell)
If you were at Salt River Fields on the evening of Oct. 22, you witnessed history.
In the second inning, Mets prospect Drew Gilbert took a half-swing at a 3-1 pitch from Salt River starter Dylan Ray. Catcher Antonio Gomez appealed to third base umpire Darius Ghani, who ruled that Gilbert had swung.
Gilbert then countered by tapping his helmet, indicating he wanted to initiate the first-ever automated review of a checked-swing. After a few seconds, the video board showed an animation of Gilbert’s swing path and determined that Ghani’s call was incorrect: Gilbert had not swung, and the pitch should instead be ruled ball four.
Gilbert trotted to first and the first checked-swing challenge was in the books. A few innings later, Yankees prospect Garrett Martin also successfully had a checked-swing strike overturned via video replay.
Here’s video of the procedure as shown on the stadium video board:
Throughout the game’s history, the definition of what constitutes a swing has been—at best—nebulous. Fans are familiar with the normal procedure for appealing a half-swing: The batter checks his swing, then the catcher asks the umpire to appeal to the umpire at first or third base, who then makes a judgment based on what he or she saw.
There is no concrete definition for what does or does not constitute a swing. Rather, the decision is based solely on the umpire’s decision. When Gilbert asked for the review, a step was taken toward defining a swing and taking potentially game-swinging decisions off of the umpires’ shoulders.
So, what does the review consider a swing? It’s complicated.
As currently being used for the challenge rule, the bat must go more than 45 degrees past a plane parallel to the front of home plate. This is a pretty hitter-friendly definition of a checked swing.
As is usually the case with experimental MLB rules in the minors or the AFL, the checked-swing challenge rule may be tweaked as MLB gets more information.
Here’s how Scottsdale manager Dennis Pelfrey explained the new system, which went into effect that day.
“They show a dotted line on the screen, and if the bat touches that dotted line, then it’s a swing,” Pelfrey said. “And that’s a 45-degree angle from the knob of the bat through the barrel, with home plate being the zero line.”
The video board animation goes like this: First, it shows the movement of the bat from the side. Next, the image shifts to an overhead view with the bat frozen in its final position. Then, a dotted line is drawn through the barrel and knob of the bat. If the bat’s barrel is judged to have traveled more than 45 degrees past its final stopping point, then it is judged a swing. If it moves less than 45 degrees, then it’s not a swing. It is not clear which way the call would go if the barrel lands at exactly 45 degrees.
In the above example, Gilbert stopped his swing almost immediately before pulling the bat back. His swing’s momentum carried the barrel forward just a few inches farther than its final stopping point, which led to a “no swing” call. Later on, Martin’s barrel went farther than Gilbert’s, but the animation showed he held up just shy of the 45-degree line, also resulting in a no-swing call.
Teams get two checked-swing challenges per game, regardless of the outcome. If they’re successful on both, the challenges are gone. If they’re unsuccessful on both, the challenges are still gone. If both challenges are used before the ninth inning, the team gets one more for the ninth inning.
Much like other rules that have been tested in the Arizona Fall League, this is likely only the first step toward a version which could one day reach the big leagues. There will be tweaking and testing and trial and error. If the system does come to MLB, it will give teams and umpires one more tool to help ensure the most accurately called game possible.
“I think if we have the capabilities to dial it in and get it right,” Pelfrey said. “I think it’s really important having it for some of those big moments in games, because the check-swing for umpires, you know, regardless of how dialed in you are or focused you are, that’s a really tough call. I mean, the bat’s in and out of the zone so fast. It’s a 50-50 ball. I mean, it’s a 50-50 ball every time.
“I think if in big moments of games, if we can get those things right, I think it’s better for the game.”
