Match Play - Control of Opponents Ball

Question
Ken,
I wandered into your site via a google search started by a rules discussion.  I hope you can help.
The basic question relates to match play and if a player may direct their opponent to leave their ball on the green before a shot is played.  I understand that the opponent may mark their ball (in order to properly replace it if struck).  I had thought that a player controlled an opponent's ball and that a player could require the opponent to leave their ball.  Some of my friends, and apparently the USGA, think this is not the case and has not been a feature of the rules since 1984.
This "USGA" position does not make sense to me, either in the specifics of the rule or with the intent of the game.
Any insight would be most apprectiated.

Answer
Hi Paul,

Yes, I believe the rule changed some time ago. Used to be your could request your opponent (in Match Play) to mark and leave his ball so that your ball could be stopped by it or deflect off of it into the hole.

I think the reasoning was that a player should not have an artificial advantage when compared to stroke play. Many match play championships have stroke play qualification rounds, where each player is playing against the field.

Hope this helps.

Ken Tannar