Fidelity of LifeTrace gap-quality scores. Semi-logarithmic plot of observed frequency of deletion errors as a function of assigned gap-quality score of the preceding base in the alignment for the MegaBACE chromatogram sets (primer and terminator) analyzed. The gap-quality score of the base preceding the gap captures the quality of the gap to the next called base, that is, low gap-qualities indicate a high probability that another base might be between this and the next called base indicating a high likelihood of a deletion error. InLifeTrace, gaps are considered a call. Observed error rate indicates the fraction of incorrect gaps (missed true basecall in between) out of all called gaps; ideal line, the same as in Figure 8. Bin width was 4 quality units.