user: Question: What is the 1993 value with a 1R in 1991 and SF in 1990?
Columns: ['Tournament', '1990', '1991', '1992', '1993', '1994', '1995', '1996']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Grand Slams', 'Grand Slams', 'Grand Slams', 'Grand Slams', 'Grand Slams', 'Grand Slams', 'Grand Slams', 'Grand Slams']
SQL:

assistant: SELECT "1993" FROM "Table" WHERE "1991" = '1R' AND "1990" = 'SF';