SELECT
    USER_ID AS USER
    ,POINT AS PT
    ,ROUND((((point - AVERAGE)*10)/SQRT(AVG(var) over ())) + 50,1) AS DEV_VAL
    /*,AVG(var) over ()
    ,SQRT(AVG(var) over ())
    ,((point - AVERAGE)*10)/SQRT(AVG(var) over ())
    ,(((point - AVERAGE)*10)/SQRT(AVG(var) over ())) + 50
    */
FROM
(
    SELECT
        *
        ,AVG(POINT) OVER () AS AVERAGE
        ,(POINT - AVG(POINT) OVER () ) * (POINT - AVG(POINT) OVER () ) as Var
    FROM TEST_RESULTS
    WHERE TEST_ID=100
)
ORDER BY DEV_VAL DESC,USER ASC