This is an arbitrary decision.

这是个武断的决定。

Why 18?It's most likely an arbitrary decision, but why not 16, or 20?

这估计是个任意的决定，但为什么不选16个， 还是20个呢？

When he is confronted with a dilemma, he usually makes an arbitrary decision by throwing a coin.

当他进退两难时，总是采用抛硬币的方法来任意做出一个决定。

Breed standards come about as a result of history, function and arbitrary decision that some features make a breed - and some do not.

犬种标准的形成是一个历史、功能以及对于是否属于这个犬种的特征的明辨的结果。

Chelsea themselves have responded to the punishment by calling it "an extraordinary arbitrary decision" and said they "will mount the strongest appeal possible.

切尔西方面则对该处罚做出了回应，称之为“极端武断的决定”，还说他们“将尽最大的努力去争取上诉”。