SELECT USER_ID AS USER, POINT AS PT,
CASE WHEN VARIANCE = 0 THEN 50 ELSE ROUND((POINT - AVERAGE) * 10 / SQRT(VARIANCE) + 50, 1) END AS DEV_VAL
FROM (SELECT USER_ID, POINT, AVERAGE, AVG(POWER((POINT - AVERAGE), 2)) OVER() AS VARIANCE
FROM (SELECT USER_ID, POINT, AVG(POINT) OVER() AS AVERAGE
FROM TEST_RESULTS
WHERE TEST_ID = '100'))
ORDER BY DEV_VAL DESC, USER ASC