Yes, Strength of Victory. Sorry for the typo.
I think all the online calculators are only using the current strength of victory, but this neglects the logical W16-W17 assumptions of Seattle beating the Cards a second time and the 49ers beating Seattle that are required for this tie breaker to even come into play. Those two results would increase SF's Strength of Victory win % and drop Seattle's SoV win %.
Currently - without adding the presumed W16 and W17 results of LAR > SF, SEA > ARZ and SF > SEA (both teams finishing 12-4) the SoV % is the following after you throw out the common team victories in W1-W15:
SF: 28-26-1
WAS - 3-11
NO - 10-3
GB - 11-3
ARZ (2nd Game) - 4-9-1
SEA: 33-23
ATL - 5-9
MIN - 10-4
PHI - 7-7
SF - 11-3
This is why things show SEA with the SoV tie breaker right now - because they are counting SEA's victories over SF as part of the formula vs. SF's 2nd victory over ARZ. But in the scenario that would require this tie breaker those games would be canceled out, leaving it to just the other three opponents for each team.
[ Edited by captveg on Dec 16, 2019 at 2:26 PM ]