The retreat began on the 120th day of the campaign. At first everything went reasonably well, although the rate of movement was seriously hampered by the impedimenta, and the army took five days to cover the first sixty miles. After two days of heavy rain, the weather turned fine, but the nights were already cold. There was, at first, few signs of Russian activity. Kutusov was aware of Napoleon's move the day it started, his vastly superior cavalry bringing him plenty of intelligence; but the Russian general appeared to be in the grip of complete lethargy. As we have seen no effort was made of follow up after Vinkovo; now, on the 19th, no immediate attempt was made to block Napoleon's road. Olnly on the 22nd did Doctorov's corps leave Tarutino, marching to shadow Napoleon's main column and then slipping ahead in an attempt to seize the important road junction of Maloyaroslavets before Eugene's IVth Corps (at the head of Napoleon's main column) could occupy it.
a rainy start to the retreat
~ D. Chandler, The Campaigns of Napoleon, p.820