Couple baseball Q's

Can a fielder at full speed go after a foul ball, vault off the ledge of a low wall and leap well into row F to catch the ball? (Think how basketball players used to leap into the stands except the baseball guy will be crazy into the fans having used the wall to vault into the stands)

second Q: A ball goes into the ivy at Wrigley knocking loose a second ball (the first ball disappeers) everyone thinks the second ball is the first one and the runner is tagged out.

Then the manager notices how old and grimy looking the ball is and claims the runner cant be out cause its not the original ball. Result?

At least one foot must be within the playing surface to make a legal catch. That include “over” the playing field. So if he’s standing in, or leaping over, row F; no catch. Foul ball.

On the second one, I think the batted ball would be considered dead in the ivy. The batter gets a double, nobody can be tagged out with the old ball.

With the trend of extending the protective screens down the lines, there is less opportunity to jump into the stands these days.
If this famous (and ill-advised) Derek Jeter catch happened today, I guess he would have been caught in the net? Or maybe it would stretch and then send him back the way he came? Boing.

Along the same lines, let’s imagine a different play at Wrigley Field:

Kris Bryant hits a pop fly that the wind is pushing towards the bleachers. Mookie Betts (interleague game) drifts back. Judging that the ball will land in the basket, Mookie jumps up, but towards the wall. He uses his non-gloved hand to grab the chain link basket while simultaneously pushing off the wall with his foot. Assume no sliding in the ivy, or getting hurt in the action at all. All variables favor Betts in this hypothetical.

Could he stretch his glove hand over the basket while using the basket itself to aid in the attempt by pulling himself up with it?

Weird question, I know. And virtually no chance of it ever being done. But I’m not interested in the physics of it; just the concept. Would using a part of the stadium in an attempt to catch the ball be allowed? It’s seems to me like there’s an inherent difference between his action in this hypothetical and someone using the wall in any other stadium to try to rob a batter of a home run.

Per rule 5.09, yes, Mookie is allowed to hoist himself up by the basket and as long as his feet are over the playing surface, it’s a valid catch.

I don’t think any specific rule exists to cover this. However, for things not specifically covered, the umpires have the power to make whatever ruling seems fair. The fair ruling here is obviously to reverse the out call and revert to the existing ground rule that a ball lost in the ivy is a double.

Right, I think it would be treated the same as if a decoy ball was thrown onto the field by a fan. This scenario also is probably not explicitly covered in the rulebook, but I think you just have to ignore the decoy ball once it’s found out.