Like naff plastic wristbands, these are the must-have accessory of the modern international bowler. The idea is to deliver a pace of significantly reduced pace, while at the same time turning your arm over at the same speed so as to deceive the batsman. This change of pace can be achieved by a change of grip, or a late tweak of the wrist. The best exponents - Courtney Walsh, Chris Cairns - are lethal. The worst - no names mentioned - tend to be smacked clean over cow corner for six.