“方差” means “variance,” “型” means “type,” and “选手” means “contestant.” The variance, an important concept in statistics, is a measure of variability. It is calculated by taking the average of squared deviations from the mean. Variance tells you the degree of spread in your data set. The more spread the data, the larger the variance is in relation to the mean. This Chinese expression, literally translated as “variance-type contestant,” coined by Chinese netizens, refers to students whose performances are not steady and therefore score quite differently when taking various exams (producing a spread data set of exam scores).
Example:
A: 你儿子这次考试又是全班第一吗？
Nǐ érzi zhècì kǎoshì yòu shì quánbān dìyī ma？
Was your son top of his class in the recent exam?
B: 没有，他是方差型选手，这次都没进前十。
Méiyǒu，tā shì fāngchà xíng xuǎnshǒu，zhècì dōu méi jìn qiánshí。
No. His academic performance is not steady. He’s not even in the top 10 this time.