Lost ball

[Phinfan]

My tee shot on par 4 hole was hit in the middle of fairway visible to all players in my group. As we walked towards green we watched a person from the fairway next to us walk out close to where my ball was and swing. I knew he was by my ball but not sure if he hit it. When we got to spot sure enough ball was gone. Is this considered a lost ball?

[cnosil]

20 minutes ago, Phinfan said:

My tee shot on par 4 hole was hit in the middle of fairway visible to all players in my group. As we walked towards green we watched a person from the fairway next to us walk out close to where my ball was and swing. I knew he was by my ball but not sure if he hit it. When we got to spot sure enough ball was gone. Is this considered a lost ball?

Rule 9.6 should be where you start

If it is known or virtually certain that an outside influence (including another player in stroke play or another ball) lifted or moved a player’s ball:

• There is no penalty, and

• The ball must be replaced on its original spot (which if not known must be estimated) (see Rule 14.2).

This applies whether or not the player’s ball has been found.

But if it is not known or virtually certain that the ball was lifted or moved by an outside influence and the ball is lost, the player must take stroke-and-distance relief under Rule 18.2.

If the player’s ball is played as a wrong ball by another player, that is covered by Rule 6.3c(2), not by this Rule.

Penalty for Playing Incorrectly Substituted Ball or Playing Ball from a Wrong Place in Breach of Rule 9.6: General Penalty Under Rule 6.3b or14.7a.

If multiple Rule breaches result from a single act or related acts, see Rule 1.3c(4).