Originally posted by TheNuisanceBird
Anakin hadn't eat or slept for several days as noted in the ROTS novelization. This was probably countered by him having to protect Palpatine. From what we saw in the video his rage wasn't prompted.
They did have him 1v1 Tyranus during Palpatine's ritual in TCW (and he won all on his own).
Either way, where Vader stood before Sidious talked him into drawing on his rage has no bearing on how strong he was by the end of Operation: Knightfall.