When Vio was completing his coaching badges, he wrote a thesis called Set pieces: the 15-goal striker, which later influenced the book That Extra 30 Per Cent. This was while juggling a job as a clerk at Unicredit in Venice.
The work was inspired by his time at Serie D outfit Il Quinto di Treviso, and in particular, two twins that used to play for him.
Vio strategically encouraged the brothers, who no one could tell apart, to stand facing the goalkeeper when they had free-kicks and just stare into their eyes.
Not only did that unnerve defenders, who couldn't decide which one was their man, it also freaked out keepers.