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 championships had at most 900 previous points .
SELECT COUNT("championship") FROM table_204_651 WHERE "prev. points" <= 900
SELECT COUNT("championship") FROM "table_204_651" WHERE "prev. points" <= 900