R3 "interferes" with F5 on line drive
 

PLAY: With R3, batter hits a low, scorching line drive toward the 3rd base bag. F5, playing near and even with the bag, lunges forward to catch the ball; however, F5 is prevented from catching the ball as R3 is diving back toward the bag. The contact with R3 prevented F5 from catching the ball. The batted ball touches neither the runner nor fielder and hits the line beyond 3rd. Fair ball!

R3 did nothing intentional and was clearly just making an attempt to dive back to the bag as the batted ball, for all practical purposes, amounted to a "pick off" throw.

Considering that a runner who hinders a fielder making a play on a batted ball is to be called out, whether intentional or not, it seems "wrong" that this runner should be called out for interference. Any attempt by the runner to do anything but immediately return to the base would have certainly resulted in a double play.

Yet, I'm thinking that this runner probably should be called out for interference. The "impossible situation" was completely the making of the offense. But, would it be a double play based on the fact that the runner's interference prevented a certain double play?

Opinions?

Call R3 out. Put BR on first. Certainly no double play in OBR. Possible by rule, I suppose, in FED, but I'm not going there.

Why was the runner in fair territory? No one at any level teaches coming off 3B in fair territory.

It's interference. Too bad.

A runner could "accidentally" get hit to stop a DP. And it would be hard to call it willful and deliberate in the situation you described.

... because the base is in fair territory. Even if a runner leads off in foul territory (as they should, like you pointed out) they have to momentarily reenter fair territory to return to the bag, just as a batter-runner has to leave the running lane to touch 1st.

In this case, R3 was not hit by the batted ball, he simply hindered F5's ability to catch it.

Nope. You dive back just like a pick at 1B. Stay foul - reach to the edge of the bag. Keeps you farther from the tag attempt that way and prevents getting hit by a fair ball too. And you said that R3 dove.

I understand that. Just giving an example of how to stop a DP.

Actually, runners (on 3rd) are taught to take their leadoff in foul territory (so as not to get hit by a fair batted ball, like you said) but to return in FAIR territory (after the pitch) so as to block any attempt on the part of the catcher to pick him off - forcing the catcher to throw around him or, better yet, the thrown ball hits the runner and is deflected away allowing him to score. "Lead off in foul, return in fair" is the proper way.
This is proper technique: https://www.youtube.com/watch?v=YaE-725FNCU

In any case, none of this is the point of the question. An answer to a rules question is never, "That would never happen" or "The player shouldn't do it that way." There should always be an answer; because weird things do happen and players sometimes don't do things the way they should.

Maybe return fair if possible on a pick attempt because you can see it coming. It isn't always.

A batted ball is not the same. It's a surprise and it gets there much faster.

You lead off as far from the base as F5.

The closer to HP the more foul you get.

I'm trying to imagine the geometry of this. Seems most likely the runner & the fielder would meet on or in the vicinity of the bag going in opposite directions, & that the momentum of the runner might carry him sliding over the base even if he initially touched its foul edge only, leading him to cut the legs out of the fielder.

Is the call in any way dependent on which of them gets to the base earliest? If the runner is there first, can he still be called for interference if while still in contact with the base he hinders the fielder's play by even inadvertent contact?

I'm having a hard time figuring how a runner diving back to the bag can interfere with the ability of a fielder make a play on this ball. This is one of those situations I better have contact between the runner and the fielder which clearly prevents the fielder from making a play on this ball. I guess if she was in fair territory (and not doing what her coach tells her to do) I could see it, but otherwise I have a hard time picturing actual interference on this play.

Although the scenario may be entirely academic. the geometry at 3rd base makes the play unlikely, unlike a thrown ball, there is no "intent" in the rule for interference with a fielder on a batted ball. More likely is the same play at 1st or 2nd. The only exception the rules give us on an infield fly.

If a runner is legally occupying a base, interference with a fielder must be intentional to be illegal.

Nope. There is no exception for interference with a fielder on an infield fly.