>Spaseebo. Ochen khoroshaw. :-) But, why the lowest values instead of the highest?
This is because
... ORDER BY Field
is the same as
ORDER BY Field ASC
So, random values are generated, the records are sorted in ascending order by this field (since ASCending is the default), and then the first "n" records - in the specified order - are selected.
Of course, to obtain 150 random records, it is quite irrelevant whether you select the first 150, the last 150, or even (if there are enough records) the first 150 that have a value higher than 0.5, for example.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)