tag up

[Guest scott]

First and third one out.  Flyout to center.  Runner on third tags runs home.  Runner on first thinks there are two outs runs to second. Center fielder throws ball to shortstop who tags runner from first who is now standing on second.  Is the runner on second out? or must first base be touched? Does the run count from third if he touched home before runner at second was tagged? 

[johnpatrick]

Assuming, in the mind of the umpire, it was an unmistakable appeal (most likely would be), the runner would be out.  This is a timing play.  If the runner scores before the runner is tagged, the run would count.

[maven]

A retouch appeal can be made by tagging the offending runner or the base he is required to retouch.

Yes, it's a time play, which means R3 almost always scores.