CREATE TABLE table_1710426_2 (best_10_year_period VARCHAR2, best_15_year_period VARCHAR2)

Which people had the best 10-year period when Fischer had best 15-year period?
SELECT best_10_year_period FROM table_1710426_2 WHERE best_15_year_period = "Fischer"
SELECT "best_10_year_period" FROM "table_1710426_2" WHERE "Fischer" = "best_15_year_period"