set threads as 'read' without reading them?

Is there any way to set a thread as ‘read’ without actually opening it to read it? The point here being so that unless new posts get added to them, they will drop lower on the list (and not be on the first page of threads).

I’m not sure I understand what you want, here. A thread’s position on the list depends only on when the last reply was. It makes no difference at all whether you or anyone else have read the thread, only when it’s been replied to.

Of course, you could open a thread and just immediately close it, but I don’t think this will do what you think it will do.

Apparently you can only mark ALL threads read, which you can do either from the hyperlink on the Straight Dope front page:

Straight Dope Message Board front page
>http://boards.straightdope.com/sdmb/

Or select “Mark forums read” from the drop-down menu under the “Quick Links” hyperlink on most every SDMB page.

This is probably not what you wanted, but it appears you can’t get what you want, in this instance, anyway. Sorry about that.

your humble TubaDiva
Not even if you try sometimes.