bǎi lǐ tiāo yī
one in a hundred
cream of the crop
Bǎi lǐ
two-character surname Baili
xíng bǎi lǐ zhě bàn jiǔ shí
lit. ninety li is merely a half of a hundred li journey (idiom)
fig. the closer one is to completing a task, the tougher it gets
a task is not done until it's done