it's anyone's call
原文解釋: This expression is used when the result of a game, contest or election is difficult to predict.
or a situation in which any outcome is equally likely
中文解釋: 勝負難分, 或人人平等且有機會之意思
A. It's anyone's call to organize the Christmas dinner, any volunteers?
B. I will, I hava some great ideas.
A. The professor said it was anyone's call to think of the discusion material for next week!
B. Great, you should volunteer. He rarely gives that opportunity.