[MrForbes]

I'll pile on....pincers mostly push the ball away from you, while rollers suck it in. But you might want to play with the ball, and make a bumper, and see how the ball behaves when you drive into it, on carpet, with a bumper, at different heights. You don't really need a running robot to do this, you can fake it with some cleverness, some pieces of wood, and a student pretending he/she is the robot. Having a bumper will also help if you are working on designing a roller mechanism, because the ball pickup thingy will likely involve the bumper in it's design.

If you can deliver the ball to the low goal, you can also deliver it to an alliance partner. Design for both, and you can either help your partners, or score on your own.