Polynucleotide sequencing methods include incubating unlabeled nucleotides with a cluster of template polynucleotide strands having the same sequence when the identity of the previously added labeled nucleotide is being detected. The detection step provides time for the addition of the unlabeled nucleotides to be incorporated into the copy strands in which the previously added labeled nucleotide did not get incorporated. Thus, at the end of the detection step, all or most of the copy strands will be in phase and ready to incorporate the appropriate labeled nucleotide in the subsequence incorporate step.