Saki doesn't understand why she was taken to play mahjong but that's where Saki and Nodoka met. Nodoka wins but questions Saki's playing style so she asks for another game.
If you think about it, getting plus-minus
zero each time is just impossible.
إن فكّرتِ بالأمر ستجدين أنّ الحصول على صفر زائد-ناقص
 في كلّ مرّة أمر مستحيل
Si lo piensan, sacar más-menos 
cero cada vez es imposible.
En y repensant, 
c’est impossible de faire zéro à chaque fois.
Ragionandoci su, fare +/- 0 ogni volta
 è praticamente impossibile.
Pensando bem, é simplesmente
impossível zerar sempre.