Q: What do the three different digital DDH formulas (d0,d4,d6) mean?

Table 3 of the TYGS result page contains the pairwise dDDH values between your user genomes and the selected type-strain genomes. The dDDH values are provided along with their confidence intervals (C.I.) for the three different GBDP (Genome BLAST Distance Phylogeny) formulas:

- formula
*d*(a.k.a. GGDC formula 1): length of all HSPs divided by total genome length_{0} - formula
*d*(a.k.a. GGDC formula 2): sum of all identities found in HSPs divided by overall HSP length_{4} - formula
*d*(a.k.a. GGDC formula 3): sum of all identities found in HSPs divided by total genome length_{6}

While formulae *d _{0}* and

More info on these formulas and the underlying GBDP method is found in the literature.