CREATE TABLE table_204_651 (id DECIMAL, "date" TEXT, "championship" TEXT, "location" TEXT, "category" TEXT, "surface" TEXT, "prev. result" TEXT, "prev. points" DECIMAL, "new points" DECIMAL, "outcome" TEXT)

how many more previous points does the australian open have than the qatar total open ?
SELECT (SELECT "prev. points" FROM table_204_651 WHERE "championship" = 'australian open') - (SELECT "prev. points" FROM table_204_651 WHERE "championship" = 'qatar total open')
SELECT (SELECT "prev. points" FROM "table_204_651" WHERE "championship" = 'australian open') - (SELECT "prev. points" FROM "table_204_651" WHERE "championship" = 'qatar total open')