SELECT P.player_id AS playerid, P.score AS score, SUM(P.one) AS rank FROM
  (SELECT sum(change) AS score,player_id,1 as one FROM player_points GROUP BY player_id) P,
  (SELECT sum(change) AS score,player_id,1 as one FROM player_points GROUP BY player_id) Q
    WHERE P.score<=Q.score
GROUP BY P.player_id
ORDER BY rank
;