To have MATCH to return the position of nearest value, the column where you search for match (99 in your example) must be sorted in right order - otherwise when you are searching match p.e. for 5 in values list 1, 3, 6, 4 in growing order, the result will be 2 (the position of number 3) instead of 4 - because at position 3 is number 6 which is greater than 5. And value list 1, 3, 2, 4, 6 for same example will give also 2 as result, as at position 3 is number smaller then previous one.