He interviews legends such as Jessica Fridrich, who deduced some of the first algorithms for solving the puzzle speedily based on the mathematics of group theory. Writer Scheffler, who achieved his first “sub-20” time in 2015, takes us inside the world of competitive cubing. For the rest of us, unscrambling the puzzle at all is next to impossible. To those who know how, the Rubik's cube can be solved easily in less than 20 seconds. Cracking the Cube: Going Slow to Go Fast and Other Unexpected Turns in the World of Competitive Rubik’s Cube Solving
