A method includes decoding a code word of an Error Correction Code (ECC), which is representable by a set of check equations, by performing a sequence of iterations, such that each iteration involves processing of multiple variable nodes. For one or more selected variable nodes, a count of the check equations that are defined over one or more variables held respectively by the one or more selected variable nodes is evaluated, and, when the count meets a predefined skipping criterion, the one or more selected variable nodes are omitted from a given iteration in the sequence.