Answer
The key to Wolverhampton Wanderers' ascent to the Premier League in 2017-18 can be attributed to their first-choice goalkeeper, John Ruddy. His exceptional shot-stopping, command of the box, and distribution skills provided a solid foundation for the team's defensive solidity. Ruddy's consistency and leadership qualities played a crucial role in securing Wolverhampton's promotion from the Championship and their return to the top flight of English football after a six-year absence.