So like in tennis, usually it's win-lose; it always adds up to zero-zero-sum. But if you're playing doubles, the person on your side of the net, they're in the same boat as you, so you're playing a non-zero-sum game with them.
Pa kao i u tenisu, obično postoji pobjeda - poraz, zbroj uvijek iznosi nula-naspram-nule, ali ako igrate parove, osoba s vaše strane mreže dijeli vašu sudbinu, tako da s tom osobom igrate igru sa zbrojem-nejednakim-nuli.