Challenge system approved!

[igor67]

I do assume we will start to see some close challenges in later innings eventually. Certainly once you get into the 7th inning or so if you are talking about a close pitch on a full count with the bases loaded it's hard not to say you burn a challenge for example. My guess is that teams will tend to be conservative at first because they want to be able to challenge that if it comes up, but they will eventually want to be challenging some calls earlier in important situations.

[RobDeer 45]

I'm happy with a minimal approach to the automated strike zone.  I think having a fully automated zone is going to take too much away from the game.  I actually hate the idea of it.  There is so much art to pitch framing and a pitcher using an umps zone, when he's consistent, to his advantage.  I do think having the challenges available for when they miss is a good idea, but let's keep the umps calling balls and strikes.  Also, could challenges only be successful if they are clearly outside of the zone vs missing by a millimeter?  Part of the entertainment of baseball is the back and forth with the umps and the fans reactions to what they think are bad calls.  It feels like we will lose a lot.  The game will feel uneventful on all called pitches.  

My one concern with the challenges will be the coaches getting instant feedback to batters with some sort of signal or noise.  That could be tough to monitor.  

I think it will be funny when you get some goofy guy like a Manny Ramirez, who won't listen to his manager and will wildly use challenges and burn them up in the first inning.  I don't know of Manny is the right example but was looking for a guy who is in his own world.

[young guns]

14 minutes ago, RobDeer 45 said:

My one concern with the challenges will be the coaches getting instant feedback to batters with some sort of signal or noise.  That could be tough to monitor.

It doesn't seem like that will be a concern.  My understanding is the players request must be instant, which would leave no time for any relay system even if the manager had a monitor in the dugout.

[titanrick]

21 hours ago, Cool Hand Lucroy said:

So, having watched tennis for years and years, I have to say the the challenge system feels far superior to me than the full-on automated line calls. There are a few reasons for this (no particular order):

1) The system sometimes can crash, meaning the game cannot continue, and there are occasionally lengthy delays.

I hadn't thought of the system crashes.  I believe the way the system works is the ump wears an earpiece and either hears "Strike" or nothing at all for each pitch.  If the system malfunctions, he would hear nothing even if it's clearly a strike.  I also worry about umps trying to play the hero and ignoring what the earpiece tells them.

I appreciate you laying out your thoughts, CHL.  I understand what you're saying about the limitations of the system, but moving to a challenge system is already submitting to its use as the "authority".  And once we get to that point, why not make every call correctly and instantly according to that system?  Issues like pitches being too low where they shouldn't be considered a strike can be addressed by modifying the strike zone box.  They are already taking into account each player's height, so that type of modification, if needed, would be trivial.

I keep going back to this: in five years, when the fully automated system is in place, will there be any baseball fans anywhere who reminisce about the "good ole days" when a horrible pitch call could swing an entire game? When some balls were strikes and some strikes were balls?  I can't imagine that will be the case.

[igor67]

I believe based on the example from tennis above that the concern over fake accuracy of the ABS system is real. It is generally more accurate than umpires of course, but just like every measurement tool it has a limit to it's accuracy. Do we really want seam-gate when a team finds a way to get the seams to stick out just a little more and see if the ABS system can pick up that extra mm? 

[markedman5]

For those wondering……we are 12th in the league in benefiting from missed calls……obviously not all calls created equal……..Cubs have benefited more than we have.

 

[AKCheesehead]

It will be interesting to see how the percentages play out for amount of challengers (batter vs pitcher vs catcher) as it would seem to me that the pitcher and catcher should generally be the ones with the highest confidence that the call was incorrect.  The catcher should definitely know.  

[titanrick]

2 hours ago, igor67 said:

I believe based on the example from tennis above that the concern over fake accuracy of the ABS system is real. It is generally more accurate than umpires of course, but just like every measurement tool it has a limit to it's accuracy. Do we really want seam-gate when a team finds a way to get the seams to stick out just a little more and see if the ABS system can pick up that extra mm? 

Wouldn't those doctored baseballs be in use for both teams during a game?  I'm not seeing how that would benefit one team over another.

[owbc]

1 hour ago, AKCheesehead said:

It will be interesting to see how the percentages play out for amount of challengers (batter vs pitcher vs catcher) as it would seem to me that the pitcher and catcher should generally be the ones with the highest confidence that the call was incorrect.  The catcher should definitely know.  

In the minors the success rate is:

Catchers: 56%
Batters: 50%
Pitchers: 41%

I'm guessing most teams will ban pitchers from challenging and batters will be instructed to only challenge obvious misses. Framing will still be important because close calls are unlikely to get challenged except in high leverage situations. Challenge success rate also needs to be factored into catcher value somehow. A catcher with a >75% challenge success rate could add a ton of value. 

[AKCheesehead]

6 minutes ago, owbc said:

In the minors the success rate is:

Catchers: 56%
Batters: 50%
Pitchers: 41%

I'm guessing most teams will ban pitchers from challenging and batters will be instructed to only challenge obvious misses. Framing will still be important because close calls are unlikely to get challenged except in high leverage situations. Challenge success rate also needs to be factored into catcher value somehow. A catcher with a >75% challenge success rate could add a ton of value. 

Those success rates track with what I read on MLB's data on it from spring training too.  But what I was specifically thinking out loud about was overall challenges, regardless of success.  

I agree with your thoughts about catchers adding value by challenges and success rate.  Inside/outside any catcher ought to have a good grasp on.  A keen eye and understanding of the top/bottom of the zone as it pertains to the size of each batter could be where some guys really shine.  It'll be interesting.

[igor67]

39 minutes ago, titanrick said:

Wouldn't those doctored baseballs be in use for both teams during a game?  I'm not seeing how that would benefit one team over another.

It was a hypothetical example of how imagining we have unlimited precision isn't really a thing. In this case maybe one team figures out an epoxy for pitchers to wear on their nails and they just pick at a seam a bit to raise it. The balls go out of play often enough that it would be a 1 sided benefit.

[wntrtxn21]

I think the system will be fully automated in 3 years. No more catchers "stealing" strikes, no more hitters and managers getting upset with horrible calls by umps. Hitters and pitchers  no longer have to adjust to the ump's zone that often changes as the game goes on. If the system goes down the solution is simple and almost instant. The ump is still behind the plate looking at foul tips, swings, etc.... If the system fails, he calls balls and strikes like they used to until the system is up and running again. The challange system is still in place. 

[Cool Hand Lucroy]

5 hours ago, titanrick said:

I hadn't thought of the system crashes.  I believe the way the system works is the ump wears an earpiece and either hears "Strike" or nothing at all for each pitch.  If the system malfunctions, he would hear nothing even if it's clearly a strike.  I also worry about umps trying to play the hero and ignoring what the earpiece tells them.

I appreciate you laying out your thoughts, CHL.  I understand what you're saying about the limitations of the system, but moving to a challenge system is already submitting to its use as the "authority".  And once we get to that point, why not make every call correctly and instantly according to that system?  Issues like pitches being too low where they shouldn't be considered a strike can be addressed by modifying the strike zone box.  They are already taking into account each player's height, so that type of modification, if needed, would be trivial.

I keep going back to this: in five years, when the fully automated system is in place, will there be any baseball fans anywhere who reminisce about the "good ole days" when a horrible pitch call could swing an entire game? When some balls were strikes and some strikes were balls?  I can't imagine that will be the case.

I don't think any of this is unreasonable. There are good arguments for the consistency of the all-time ABS system. And, in tennis, it has certainly allowed for a very consistent flow in matches. Though I admit to being one of the tennis fans who longs for the "good old, challenge system days."

Our basic philosophical disagreement, probably unresolvable, is just that I prefer to preserve a collaborative, agreed upon, limited uncertainty (which the challenge system represents, at least in terms of letting some close calls be decided by humans, on the assumption that it's not worth arguing over everything) to the false certainty of completely automated systems. I especially wince (maybe unfairly) at the argument that "let's just get calls right" because I think the kinds of calls that most need to be made by a non-human arbitrator are often not binary. For example, I worry about ABS having its own version of the "guy came off the bag by a mm, maybe forced by the tag, and is therefore out based on the letter of the law." For my money, that's the worst thing about baseball, and it exists because we made a fetish out of replay being certain and correct. I guess, in the end, I'd rather the tech be the universally acknowledged authority in limited circumstances than all the time. Though I agree with the idea that we've already privileged its perspective. It's a good point.

It's good to disagree about this, and I appreciate the substantive conversation. I suspect you're right that we'll be fully ABS in the near future. At that point, I'll have lost the argument, and I'm genuinely okay with being in the minority. As long as the decision-making process properly grapples with these broader philosophical issues, it's part of the deal if my preferred outcome isn't the one that gets settled on.

[SeaBass]

16 hours ago, wntrtxn21 said:

I think the system will be fully automated in 3 years. No more catchers "stealing" strikes, no more hitters and managers getting upset with horrible calls by umps. Hitters and pitchers  no longer have to adjust to the ump's zone that often changes as the game goes on. If the system goes down the solution is simple and almost instant. The ump is still behind the plate looking at foul tips, swings, etc.... If the system fails, he calls balls and strikes like they used to until the system is up and running again. The challange system is still in place. 

I'm not so sure it will. Up until recently I have also been on the fully automated band wagon but I've now come around to thinking the challenge system might be the best option. It will still take watching it in action to fully convince me but I'm definitely leaning towards the challenge system being the best option.

Also, I don't actually think that Manfred or the suits in the MLB office have strong feelings about going fully automated. If they did then that would change my view on what will happen in the future. I think they're prepared to be just as satisfied with the challenge system as the players.

I get it (because I was thinking it too) the challenge system feels sentimental, like it's clinging to tradition. But the more I've read about it I feel I better understand what the baseball folks are talking about. I'm just not as convinced now as I was before that going 100% with technology is the superior choice.

Ultimately we shall see. Opinions will form more solidly as we see it in action.

[Baldkin]

18 hours ago, igor67 said:

It was a hypothetical example of how imagining we have unlimited precision isn't really a thing. In this case maybe one team figures out an epoxy for pitchers to wear on their nails and they just pick at a seam a bit to raise it. The balls go out of play often enough that it would be a 1 sided benefit.

 

If pitchers were that adept at raising seams without anyone noticing they would be doing it to get extra break on their pitches right now. 

[igor67]

7 minutes ago, Baldkin said:

 

If pitchers were that adept at raising seams without anyone noticing they would be doing it to get extra break on their pitches right now. 

Probably, but the example isn't really important. All measurements have accuracy limits and trying to push technology into areas well beyond our own eyesight's accuracy leaves things open to very goof weird exploits that are not part of the game.

[Samurai Bucky]

On 9/24/2025 at 10:25 AM, young guns said:

It doesn't seem like that will be a concern.  My understanding is the players request must be instant, which would leave no time for any relay system even if the manager had a monitor in the dugout.

Listen very carefully for the banging of garbage cans...

Someone will try to come up with some type of system.  By "instant" is it 1 second, 2 seconds?  I think it will be somewhat fluid.  1 second doesn't allow a "garbage can" type of indicator while 2 seconds might.

The best solution would be to have it be automatic.  That takes out the human element, though.  This is a good step in the right direction with is to keep the human element in place, but use the technology that is available.

[markedman5]

Worst calls of the season…….none involving Brewers interestingly enough.

 

[ErnieRilesBrianGiles]

Wow, those were really bad!

[SeaBass]

18 hours ago, markedman5 said:

Worst calls of the season…….none involving Brewers interestingly enough.

 

And these are just the called strikes. I can remember a handful of pitches that were well within the strike zone and called balls as well. Brutal.

[Team Canada]

That's the beauty of the challenge system. It's not really about the balls that are painting the edge. I think we can all live with those calls going either way, and it's amazing that they're called correctly as often as they are. But calls like those above will never happen again.

[Playing Catch]

12 hours ago, ErnieRilesBrianGiles said:

Wow, those were really bad!

Do we know how MLB will digitally determine the top of the zone for hitters? The current rule states that it is determined by "...the midpoint between a batter's shoulders and the top of the uniform pants -- when the batter is in his stance and prepared to swing at a pitched ball."

But this seems stupid for me, unless the ABS system can account for a player changing their stance from one at-bat to the next (or one month to the next).

I feel like they will need to be a bit more specific if they are going to use a system that is designed to be that specific.

22 hours ago, markedman5 said:

none involving Brewers interestingly enough.

(LOL)

[SeaBass]

23 minutes ago, Playing Catch said:

Do we know how MLB will digitally determine the top of the zone for hitters?

Yes. Pasted below is an AI summary from Google but I've also read the article and can confirm it's correct.

The MLB's automated strike zone parameters define a 17-inch wide, player-specific rectangle for the strike zone, set at the midpoint of the plate. The top of the zone is at 53.5% and the bottom is at 27% of the batter's height. The system uses Hawk-Eye technology to track pitches, making the ball/strike determination when the ball is at the midpoint of the plate. 

Strike Zone Dimensions

Width: 17 inches, the width of home plate. 

Height: Adjusted for each player's height.

The bottom of the zone is 27% of the batter's height.

The top of the zone is 53.5% of the batter's height. 

Depth: The system makes its call when the ball is at the midpoint of the plate, 8.5 inches from the front and back.

How the System Works

Height Measurement: Independent testers measure each player's height during Spring Training to establish the official zone for that player.

Players are measured standing straight up without cleats.

Pitch Tracking: Hawk-Eye cameras track the ball's trajectory to the plate.

Midpoint Call: The system determines if the ball crosses the strike zone when it's at the midpoint of home plate.

Comparison to Rule Book: This is a change from the standard rule book zone, which considers a strike a pitch that crosses any part of the three-dimensional home plate. 

[Oxy]

18 minutes ago, Playing Catch said:

Do we know how MLB will digitally determine the top of the zone for hitters? The current rule states that it is determined by "...the midpoint between a batter's shoulders and the top of the uniform pants -- when the batter is in his stance and prepared to swing at a pitched ball."

But this seems stupid for me, unless the ABS system can account for a player changing their stance from one at-bat to the next (or one month to the next).

I feel like they will need to be a bit more specific if they are going to use a system that is designed to be that specific.

(LOL)

I don't know, but these days it shouldn't be that hard for a computer to "see" both the beltline and the "shoulders" (armpit? Top? whatever they decide) for every AB and make the top of the strikezone exactly between those two points as the rulebook states.  Who knows how it will actually occur though.

[Oxy]

4 minutes ago, SeaBass said:

Yes. Pasted below is an AI summary from Google but I've also read the article and can confirm it's correct.

The MLB's automated strike zone parameters define a 17-inch wide, player-specific rectangle for the strike zone, set at the midpoint of the plate. The top of the zone is at 53.5% and the bottom is at 27% of the batter's height. The system uses Hawk-Eye technology to track pitches, making the ball/strike determination when the ball is at the midpoint of the plate. 

Strike Zone Dimensions

Width: 17 inches, the width of home plate. 

Height: Adjusted for each player's height.

The bottom of the zone is 27% of the batter's height.

The top of the zone is 53.5% of the batter's height. 

Depth: The system makes its call when the ball is at the midpoint of the plate, 8.5 inches from the front and back.

Players are measured standing straight up without cleats.

How the System Works

Height Measurement: Independent testers measure each player's height during Spring Training to establish the official zone for that player.

Pitch Tracking: Hawk-Eye cameras track the ball's trajectory to the plate.

Midpoint Call: The system determines if the ball crosses the strike zone when it's at the midpoint of home plate.

Comparison to Rule Book: This is a change from the standard rule book zone, which considers a strike a pitch that crosses any part of the three-dimensional home plate. 

That's kinda dumb if it is purely based on height, as some people are long legged and short torsoed and others are vice versa.  It should literally be measured by the kneecaps, top of the hips and top of the shoulders.  No big deal though I guess as long as it is consistent for each individual player throughout the year.