WITH t AS (
    SELECT USER_ID AS USER, POINT AS PT FROM TEST_RESULTS WHERE TEST_ID = '100'
)
, u AS (
    SELECT USER, PT, PT - (SELECT AVG(PT) FROM t) AS PT_GAP FROM t
)

SELECT
    USER
    , PT
    , ROUND(PT_GAP * 10 / (SELECT SQRT(SUM(POW(PT_GAP, 2)) / (SELECT COUNT(0) FROM u)) FROM u) + 50, 1) AS DEV_VAL
FROM
    u
ORDER BY
    DEV_VAL DESC, USER ASC
;