OK, I took Paddle2SeeFixIt, EMIL and my own work and jigged it again. I added a little bit that shrinks the bubble as it fits it. A quote from my Games Teacher at school, while learning to bowl at cricket: "Always substitute speed for accuracy." There is no point in getting the bubbles to be fast if they don't look like the real thing. Thanks to the Scratch community for helping me get this right. Paddles original notes: I looked at itsEMILagain's wonderful faster version of Circles That Kiss and I wondered how a bisection search would work in this application. So I set one up. Seems to work pretty well...hard to say if it's faster than itsEMILagain's routine though. Original notes from itsEMILagain: This is based on the idea of this project by Nid: http://scratch.mit.edu/projects/NiD/214336 i thougt i could make it faster and a lot simpler. seems like i could, doesn't it? its one sprite, one script. please comment!