There's no active non Big 4 player that reached the Top-2


Hall of Fame
After Tommy Haas' retirement. There's no active player that has reached the Top 2 that is not called Federer, Nadal, Djokovic and Murray. The current players whose highest ranking is N°3 are David Ferrer, Stan Wawrinka, Milos Raonic, Alexander Zverev, Grigor Dimitrov and Marin Cilic.



It'll take a while - Federer and Nadal have over 9,000 points, whereas no-one else has over 5,000.
No one ever bothers with the math. I've seen people saying several have a good chance of YE#1(like Goffin, Dimitrov), yet most of them have a hard time even scoring 4k points. Fedal can score 5k+ in their sleep.