My advice for chess players.

"I am very eager to hear what skills it takes to become that strong."

Study endgames and know what moves to make in the middle game to get an advantage in the endgame.

I highly recommend http://www.chessgames.com/perl/chesscollection?cid=1002457

Capablanca: "In order to improve your game, you must study the endgame before anything else; for whereas the endings can be studied and mastered by themselves, the middlegame and the opening must be studied in relation to the endgame."