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with ByUser as ( select OwnerUserId , cast(count(AcceptedAnswerId) as float) / cast(count(*) as float) as AcceptRate from posts p where p.PostTypeId = 1 and CommunityOwnedDate is null and exists ( select 1 from posts where ParentId = p.Id ) group by OwnerUserId having count(*) >= 4 ) , FirstStep as ( select AcceptRate , row_number() over ( order by AcceptRate asc ) as RowAsc , row_number() over ( order by AcceptRate desc ) as RowDesc from ByUser ) select avg(AcceptRate) from FirstStep where RowAsc in (RowDesc, RowDesc - 1, RowDesc + 1)