Trapped fly balls video review.
 

How is MLB going to handle this? Runners on base the initial call is no catch. Where do you put the runners if replay shows a catch? How about if there was a runner on third? If it were ruled a catch initially maybe he could have tagged up.

Precisely why instant replay will cause more problems than it will solve. I can agree it could be used to determine Fair/Foul on a homerun, but that is about the extent I would like to see.

The rule will say that the umpires will place the runners, manager will not be allowed to argue the placement of runners.

There's no perfect way, but what this replay will show is precisely how often the umpires are correct at the MLB level.

I'll bite
 

In most cases where a runner on third would tag up and run, they could also run on an uncaught ball. Is there really a scenario with a runner on third where there would be a significant difference?

I think it's more confusing in the normal case with a runner on second that goes halfway to third. Caught-ball, he goes back to second. Uncaught, he moves safely to third.

Replay is fine when the ball is dead. Eg. Home Runs. It's a sticky wicket with continuing action. Football, Hockey, Basketball replay is fine because the ball/puck is dead. With baseball there's a chance for another play. With rare exceptions I don't think baseball lends itself well to replay.

The problem on most traps is that they happpen coming in toward the infield. The fileder is close enough that if caught and the fielder stays on his feet the runner would probably not try to score. If he slides of tumbles there may or may not be an attempt. In that case I think that call is best left to the runner and 3B coach.

Keep traps out of the replay.

My first thought is this is all about judgement. Do you as the umpire believe the runner would have scored/advanced on that trap or not? My second thought involves the inadvertant call provision that exists in High School but not the pros. You can fix a bad call so that a team is not jeopardized in HS, but the pro game has no such qucik fix. If your replay shows a blown call on that trap, too bad for the offense. The catch is registered and the runners stay put. Teach them to tag up.

Situation
 

My point is that with less than 2 outs, R3 is going to be tagging up on a fly to the outfield. Whether the ball is caught or trapped, the fielder will have the ball in possession, and R3 will have to decide whether to advance to home at her own risk. Chances are the fielder will throw home in either case as well.

So, most of the time, both offense and defense will play the same way (whether they think the ball was caught or not) with regards to R3.

To be explicit, say U1 originally calls the batter out on a fly into right field. R3 attempts to score and is put out at the plate. On further review, the crew decides that the ball is trapped. I think in most cases it would be correct to assume that R3 would have tried to run on the hit, and continue to uphold the out at home. Same for most other plays with R3 and less than 2 outs.

I am not defending the use of replay at any level for this type of review. I'm just saying that R3 will typically be the least of the worries for the crew that has to change such a call on review.

OK same situation less than two outs it's ruled a no catch R3 is safe at home (doesn't tag) upon further review it's ruled a catch. What do you do with R3?
If you put him back at 3rd how can you assume he wouldn't have tried to tag and score? Continuing action doesn't lend itself well to replay.

I dont have one bit of a problem with the major league umpires using their best judgement in placing runners in this situation. (I wouldnt have a problem with NCAA umpires doing it either, but its not necessary yet) Even though there is no contesting these decisions by the umpires, I will bet that there will be few instances where a legitimate question arises. I also believe it will probably be pretty much a non issue next year.

Might be
 

Yes, if R3 goes halfway home on a trouble ball to the outfield, that will be a problem. My point is that this will actually be rare; usually R3 will be tagging up in anticipation of the ball being caught. At least I think that is what coaches would expect.

Clearly, I would have to be there, and I doubt I ever will be*, but if R3 really did go down the line on an outfield fly, I might take that as an indication that R3 would not have tagged up on a caught fly ball. So, on further review, I might return R3 to third base. I expect that a little later, I might be ejecting somebody from the offense.

So no, I am not a proponent of expanding instant replay this way. Here's a scenario more likely, I think, to cause grief.

One out, R2. Line drive to right field, and R2 goes halfway to third. F9 dives to his left, and U1 rules a catch. R2 trots back to second base. But, on further review, the play is ruled a no-catch. Now, do you place R2 at third? Out at home on the throw? Score the run? In all of that, where does B/R get placed?

Depending on the location of the trap, it might most likely be B/R to second, score R2. Now I might get to eject somebody from the defense.

I wonder if anybody from MLB actually reviews tape from games where these situations have occurred to see how they would play out in real life?

* I'll never be an MLB umpire, but I suppose it's possible that I'd someday be working a LL World Series, and they are also a little whacky about replay.

I agree, Jon. Placing runners is something umpires are sometimes called upon and most of us seem to do fine.

I can't tell you how many times I have had a coach say that the outfield fence has gaps at the bottom and asks how we'll handle it. I tell them to keep running and we'll sort it out. The same thing should happen in MLB with the replay in question. The CWS will have limted replay available too this year and it is about time. There's an awful lot riding on making the correct call.

Ground Rule Double
 

I'm not sure those cases are parallel. A batted ball going through a gap is a mandated 2-base award. No umpire judgment in placing anybody. Also, "just keep running" is probably bad advice to a coach on a catch/no-catch controversy. :)

Obstruction is a closer situation, I think, and we have years of practice and some official guidance for many particulars there. Even so, we still have longish threads on forums such a this one about rarer situations. The MLB umpires may be making it up as they go along, which will be interesting.

I feel you are seeing way to much here. The depth of experience in those four man crews will nullify any "rare" situations that may come up. I will stick with it being a non issue next year. The only gray areas that might be of any issue will be tag ups at third and I think you will see a coordinated effort to handle these with a strong consistency (which should aid in this being a non issue).

1) We have some crazy fields and equally wierd ground rules. I have had caoches claim that they have a pole down right field and if it hits or goes into the protected area, it is three bases. That is just one example and we have had threads dedicated to others. We use our judgement and so will the MLB guys.

2) I don't see a problem with replay reversing a catch or vice versa. If the guy tagged and is thrown out on a play that, after review, is ruled no catch. He is still out. If the guy doesn't tag and there is a catch, after review, he chose to leave early and is penalized for his bad judgement.

3) I'm pretty confident that the MLB guys will have guidelines and be skilled enough to handle the drama. Being second guessed for exercising judgement is part of the game.