The critical-snark defect-3 conjecture

Let a critical snark be a snark in which deleting any edge yields a $3$-edge-colourable graph, and let the colouring defect of a cubic graph be the minimum number of uncovered edges left by three perfect matchings. Critical-snark defect-3 conjecture. Every critical snark has defect $3$. This is motivated by computations showing that critical snarks of order at most $36$ have the asserted defect; whether the claim holds in general remains open.