t, MySQL - rextester

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#MySQL 5.7.12
#please drop objects you've created at the end of the script 
#or check for their existance before creating
#'\\' is a delimiter

DROP TABLE IF EXISTS tmpPoradi;

CREATE TABLE tmpPoradi 
    (`player` int, `wins` int, `diff` int)
;

INSERT INTO tmpPoradi 
    (`player`, `wins`, `diff`)
VALUES
    (1, 10, 12),
    (2, 8, 2),
    (3, 10, 10),
    (4, 8, 1),
    (5, 8, 7),
    (6, 10, 14),
    (8, 10, 10),
   (7, 12, 3)
;

SELECT player, wins, diff, dense_rank, rank, dense_val, prev_wins, prev_diff
  FROM
     (
         SELECT player, 
                wins,                 
                diff, 
                @dense_rank := IF(wins = @prev_wins and diff = @prev_diff, @dense_rank, @dense_rank + @dense_val ) AS dense_rank,                
                @dense_val  := IF(wins = @prev_wins and diff = @prev_diff, @dense_val + 1 , 1) as dense_val,
                @rank := @rank + 1 as rank,
                @prev_wins := wins as prev_wins,
                @prev_diff := diff as prev_diff
         
         FROM tmpPoradi,(SELECT @dense_rank := 0, @dense_val := 1, @rank := 0, @prev_wins := 0, @prev_diff := 0) r 
         ORDER BY wins DESC,diff DESC
     )  rt
  ORDER BY rank


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