There will be very, very few differences among plastic balls on todays oil. If I were you, I'd go with the best looking one.
That said, Columbia has said (somewhere; can't recall where I read it) that while the new Blue Dot is the same technical hardness as the White Dot, the shell is actually less flexible than the White Dot. That translates to, as the ball contacts the lane, less of the Blue Dot, a smaller surface area, is in contact with the lane than a White Dot. The concept is similar to that of solid resin balls and pearlized resin ball. Although the technical hardness rating is the same, a pearl of the same weight as the solid will have a smaller contact area with the lane surface. This promotes more skid, of course.
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"None are so blind as those who will not see."
