Donald Knuth’s 2025 Christmas Lecture: The Knight’s Tours

“It’s that time of the year!” read the email from Stanford Online. As he approaches his 88th birthday, Donald Knuth returned in early December for his special once-a-year “Christmas” lecture — a tradition he’s been honoring for over 30 years.

Stanford’s beloved professor emeritus reminded his audience he’s still writing “The Art of Computer Programming” — a legendary book he’s been working on for over 63 years (releasing it in installments).

But this year, he took a detour of sorts: The revered math and algorithms…