Table: tennis_stats_6
Columns: tournament
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
career_sr
career_win_loss

Question: What shows for 1997 when 1987 is 2r?
SQL: SELECT "1997" FROM tennis_stats_6 WHERE "1987" = '2r'

Question: What shows for 1993 when 1991 is grand slams?
SQL: SELECT "1993" FROM tennis_stats_6 WHERE "1991" = 'grand slams'

Question: What shows for 1987 when 1995 shows 1r, 1986 is a, and 1998 is sf?
SQL: SELECT "1987" FROM tennis_stats_6 WHERE "1995" = '1r' AND "1986" = 'a' AND "1988" = 'sf'