Every time I've ever played there's been spares, not because people thought you'd need spares, but because every individual person wanted to make sure there wou

Every time I've ever played there's been spares, not because people thought you'd need spares, but because every individual person wanted to make sure there would be at least one ball there. This doesn't solve that particular problem. Also during the warmup you need multiple balls. Then you don't have 10 people all waiting forever to take their shot.