The Borodin-Kostochka conjecture asserts that a finite simple graph with maximum vertex degree
satisfies
where
is the chromatic number and
is the clique number
(Borodin and Kostochka 1977).
Reed (1999) proved the inequality for sufficiently large maximum vertex degree. Chen (2026) obtained the explicit threshold using a randomized partial vertex
coloring and finite certified estimates. The conjecture remains open at the threshold
9.