Q&A for Drupal developers and administrators
SELECT Count(*) FROM ( SELECT (d.Id) as id FROM Posts d -- d=duplicate LEFT JOIN PostHistory ph ON ph.PostId = d.Id LEFT JOIN PostLinks pl ON pl.PostId = d.Id LEFT JOIN Posts o ON o.Id = pl.RelatedPostId -- o=original LEFT JOIN Users u ON u.id = d.OwnerUserId WHERE d.PostTypeId = 1 -- 1=Question AND pl.LinkTypeId = 3 -- 3=duplicate AND ph.PostHistoryTypeId = 10 -- 10=Post Closed AND u.Reputation > 999 AND u.Reputation < 10000 ) as t1