I would say you comprehended just fine.

I would also say I do not see a concept or point being displayed by the question or it's explination. After furthur review...

DECLARE @t TABLE

(nDex INT IDENTITY(1,1)

,valu VARCHAR(9)

,keey UNIQUEIDENTIFIER)

INSERT @t

VALUES ('a',NEWID()) , ('b',NEWID())

,('c',NEWID()) , ('d',NEWID())

,('e',NEWID()) , ('f',NEWID())

,('g',NEWID()) , ('h',NEWID())

,('i',NEWID()) , ('j',NEWID())

,('k',NEWID())

SELECT *

INTO #gT from @t;

DELETE t

OUTPUT DELETED.*

FROM @t AS t

INNER JOIN (SELECT TOP 9 nDex

FROM #gT

ORDER BY keey) AS b

ON b.ndex = t.nDex;

DROP TABLE #gT;

GO

Seems that if you ORDER BY the name or alias of the column holding the NEWID() values and join to a #temp table of the records instead of the table you are deleting from (as you delete) the code always returns as I would expect it too.

The other code would seem to never produce the same amount of joinable values to return...

So why is "none of the above" the wrong answer?