sql - Order by pairs of values -

i have set of rankings, ordered group , ranking:

group | rank ------------     |  1     |  2     |  3     |  4     |  5     |  6   b   |  1   b   |  2   b   |  3   b   |  4   c   |  1   c   |  2   c   |  3   c   |  4   c   |  5   d   |  1   d   |  2   d   |  3   d   |  4 

i want interleave groups, ordered group , rank, n rankings per group @ time (here, n=2):

group | rank ------------     |  1     |  2   b   |  1   b   |  2   c   |  1   c   |  2   d   |  1   d   |  2     |  3     |  4   b   |  3   b   |  4   c   |  3   c   |  4   d   |  3   d   |  4     |  5     |  6   c   |  5 

i have achieved desired result loops , table variables (code pasted here because got non-descript syntax error in sql fiddle):

create table rankings([group] nchar(1), [rank] int)  insert rankings values  ('a',1), ('a',2), ('a',3), ('a',4), ('a',5), ('a',6), ('b',1), ('b',2), ('b',3), ('b',4), ('c',1), ('c',2), ('c',3), ('c',4), ('c',5), ('d',1), ('d',2), ('d',3), ('d',4)  -- input declare @n int = 2 --number of group rankings per rotation -- output declare @orderedrankings table([group] nchar(1), rank int)  --   -- in-memory rankings.. deleting used rows declare @rankingstemp table(groupindex int, [group] nchar(1), rank int) insert @rankingstemp  select    row_number() on (partition rank order [group]) - 1 groupindex,   [group],   rank rankings order [group], rank  -- loop variables declare @maxgroupindex int = (select max(groupindex) @rankingstemp) declare @rankingcount int = (select count(*) @rankingstemp) declare @i int  while(@rankingcount > 0) begin   set @i = 0;   while(@i <= @maxgroupindex)   begin     insert @orderedrankings     ([group], rank)     select top(@n)       [group],       rank     @rankingstemp     groupindex = @i;      t (       select top(@n) *       @rankingstemp       groupindex = @i     );     delete t      set @i = @i + 1;   end   set @rankingcount = (select count(*) @rankingstemp) end  select @rankingcount rankingcount, @maxgroupindex maxgroupindex  -- view results select * @orderedrankings 

how can achieve desired ordering set-based approach (no loops, no table variables)?

i'm using sql server enterprise 2008 r2.

edit: clarify, need no more n rows per group appear contiguously. goal of query yield ordering, when read sequentially, offers equal representation (n rows @ time) of each group, respect rank.

perhaps this...sql fiddle

order  ceiling(rank*1.0/2), group, rank 

working fiddle above (column names changed slightly)

updated: burned int math... . should work now. forcing int decimal multiplying 1.0 implicit casting doesn't drop remainder need ceiling round correctly.