As mentioned, the name is misleading. It is not dynamic at all, just a re-calculation of compression stroke length at the intake closing point and a rough estimate where that point is anyhow. I won't say it means zip, it does give a good indication of cranking compression pressure, and if the compression is way off for the cam size.
I don't recall where the DCR relationship to fuel octane came from?
It might have been an article comparing the DCR ratios of different "pump" gas engines? The calculation is being overstated and misused for estimating octane requirements.