A soft rubber normally produce a lower throw angle than a hard rubber.
I know how different parameters for various designs for pips rubbers & blades effect throw angle but I am not completely sure about inverted rubbers
I may be wrong on this but I disagree with the statement that A soft rubber normally produce a lower throw angle than a hard rubber. I think a softer rubber will have more dwell time & release the ball later than a hard rubber which will have lower dwell time & therefore a softer rubber will have a higher throw angle.
The concept is very similar to a soft all wood blade having a higher throw angle than say a carbon outer layer blade. (On the other hand various composite matrerials have their own differences.Foe example I think Arylate may have a higherthrow angle than carbon, may be because it is softer ? I do notknow).
So to me a harder blade or harder (inverted) rubber has a flatter (& faster) trajectory (meaning lower throw angle)
I do not claim tohave lot of expertise on rubbers in 40+ ball era. But I think TSP 730 & Globe 999 have a higher throw angle than RITC Tack Speed 2000 or TSP New Magnet C. I think this is because the (0nverted) pips in 730 & 999 are shorter. This is why RITC Tack Speed 2000 & TSP New Magnet C block like a dream against a super spinny incoming loop compared to 730 or 999, though 2000 & New Magnet C can create incredibly heavy spins on their own.
Yinhe 9000c & 9000d or 9000e etc are also like this I think
TSP New Magnet C had a higher throw angle than TSP New Magnet D because TSP New Magnet D had a harder sponge. TSP 730 & Globe 999 were later available in so many sponge types to vary speed & throw angle.
i have not made too much measurements (or seen a significant differnece) in 40+ ball era between various inverted rubbers.
All non-Chinese rubbers seem like anti spin rubbers with low spin & throw angles tome so I cannot comment LOL
But as I said I may wrong on this as I honestly don't pretend to fully understand how different variables for spinny inverted rubber designs increase or decrease throw angles.