It seems in the last 10 years I have seen rubber on the PBA tour.

Didn't Danny Wiseman used to use rubber for his spare ball?  Once a ball was approved it is still approved right?

If you were to compare rubber, plastic, and urethane how would you rate them in order of strength?

Thanks,

Luckylefty

Actually only a certain super soft rubber compound used in the original LT 48 was a problem.  Most popular rubber balls from the pre plastic era were hard and would not leave black marks. 

As for how they hut, that is an interesting question. I still have an old bkack diamond from Brunswick.  I have used it several times over the past few years.  Best way to describe it is different.  Totally helpless on heavy long oil, but it reacts better than plastic on some liighter volumes. 

I can give you a couple of anecdotal experiences with my black diamond.  First occurred around 1994.  I was throwing excalibers and teal rhinos at the time.  I  got in a car wreck while out of town, and couldn't get any of my equipment home in time for league a couple of days later.  I went to the garage, and found that all I had was an old pair of shoes, an old yellow dot, and the black diamond.  I took them down to my money singles league figuring I might be able to do as well as taking my blind.  I tried the yellow dot first and really didn't get much reaction shooting about 630 for the first three.  I switched to the black diamond, and was actually able to move inside 10 board playing the track area of the synthetics.  I shot close to 700 the second 3 and actually won the sweeper for the night.  Historically hard rubber gave way to soft plastic because the plastic hit better.  However on these worn synthetics on a late shift the rubber ball read the the track very smoothly and seemed to be stronger than the yellow dot. 

A few years later we were bowling the last night of a league that we had already clinched.  I decided to take the black diamond down.  I started around 8 board and struggled to a 160 the first game on a house wall.  The second game I moved inside 10 board and again picked up the track and started striking.  I threw a 240 game.  The last game I started moving even further in, and couldn't over swing the ball if I tried.  Finished with a 260 game. 

I used the ball several times later, but these were far and away the most effective times.  Both were late shifts on heavily worn anvil lane synthetics.  Only other times it worked at all was way outside on very short patterns where even my urethane and plastic would over react.   

I had almost forgotten, but way back, Brunswick returns sometimes would return hard rubber balls on super flooded lanes.  With the amount of oil being used today,bI could see the problem

A couple more thoughts on rubber balls.  Bach the all ballsvwere three piece with a high density weight block just below the shell.  Plastic balls retained this structure, but not too long after the urethane revolution, Hammer introduced the 2 piece ball.  The modern 2 piece low rg construction matches up much better with today's softer shell balls.  For whatever reason, the old style 3 piece cores seem to ma tch up much better with the hard rubber

I owned dozens of hard rubber balls including several AMF balls.  That's something I never ran in to.