This year’s World Cup has had more goals than in recent years. The design of this year’s ball may have a lot to do with it. This year’s ball design, brazuca, is rougher than the ball used in 2010. This roughness affects how the air moves around it, and reduces the critical speed that makes the ball “knuckle”. This means that regular 50-60 mph kicks move the ball above the speed where the unpredictable motion happens. This leads to more controllable shots.