It's one of those scientific reports that feels more science than reality.
There's a reason all the pros, the manufacturers and thousands of amateur players have all said they get less spin (in general) with the plastic ball compared with the celluloid ball....... They can't all be wrong just because one study attempts to prove otherwise......
I have no problem believing the report (which is saying the plastic ball generates more spin), but I just don't see those results in the real world.
It may be because a robot can generate more spin than a human can (consistently)....... But who knows......
What? How did you come up with that implication? In fact, the study says nothing at all about which ball generates more spin.
What is says though, is that plastic balls experience more friction when contacting the table. Especially when the ball is rotating, the increased friction causes the ball to experience a force in the same direction the ball is spinning. So where does this force come from? Thin air? No, it comes from the rotation energy, which in turn is diminished.
IN FACT THIS STUDY PROVES THAT PLASTIC BALLS HAVE LESS SPIN COMPARED TO CELLULOID BALLS.
With the following caveats:
(1) As experienced by the opponent on their rubber
(2) Assuming that the plastic ball's initial spin rate, with the usual range of strokes a player has, is not so much higher that it overcompensates the spin loss due to friction on the table.
There you have it. Show it to all the fools who still live in denial.