Blake Alexander Carrington is a fictional character on the ABC television series "Dynasty", created by Richard and Esther Shapiro. The role was portrayed by John Forsythe from the first episode of the series in 1981 until its finale in 1989. Forsythe returned for the 1991 miniseries, "". In The CW's 2017 reboot of the series, Blake will be played by Grant Show.
Grant Show played Blake Alexander Carrington since the start of Dynasty.
The data said that Grant Show didn't start playing Blake until 2017.  The systems seem not to be able to calculate dates in terms of start date.