N at n
Nouns with other meanings
There are a number of other nouns which have this pattern.
I was travelling home from work and an elderly drunk made a grab at my knee.
His skill at public speaking has won him many standing ovations at Conservative Party conferences.
In the case of pretence, success and turn, the preposition at is sometimes followed by an '-ing' clause.
In its early days, the school made no pretence at being academic.
In the case of guess, the preposition at is sometimes followed by a wh-clause. This pattern is N at wh
grab guess pretence skill success turn
So have a guess at who the mystery celebrity is.