Liquid Additive, WTBA versus TBA rules
The "additive" is a plasticizer and is bound in the urethane resin from which all reactive and proactive balls are made. It only becomes a liquid again when it bleeds out of the ball. So it would not make them all illegal, just designed to fail (die/reduce in performance)after 50 to 100 games. Di-octyl phthalate or DOP is one of the plasticizers of this type. Before anyone starts contradicting me about reactives etc being urethane, they are made of urethane, or polyurethane to be more exact. The Bowlers terminology has been made simpler by referring to non reactives as "Urethane". Reactives and Proactives are close relatives to non reactive balls, one of the major differences being the traction they get on the lane surface when they heat up in the back end of the lane where hopefully there is no oil. Reactives and Proactives soften at a low temperature and can then grab the lane. A non-reactive ball would do the same but at a much higher temperature.
Theoretically, if you chill your most reactive ball and crank the shot real hard, it won't turn at all cos it can't heat up enough to grab the ball. This is of no practical use but shows the mechanism involved in making reactives hook. Please don't do this, if you get the ball too cold it'll crack and fall to pieces.
There is a guy in the States selling a treatment for bowling balls that holds the oil out of the ball and keeps the plasticizer within. (Doc's Black Magic from memory) Seems to reduce the hook rating by 10% or so, but the ball stays active at that hook rating for many hundreds of games, instead of dying. I haven't tried it but comments on the Ball reviews forum (before Scott Scriver sold the site) seemed to be positive.
On rules, TBA is about to align their rules with WTBA, so if there is a minimum size in the WTBA it will apply here for 2004.
Sumo,
Japanese Scientist/Bowler/Wrestler