Post my Christmas reading (Waterloo Rout and Retreat by Andrew W Field), I've been thinking that we sometimes underestimate the importance of retreating. Being able to break contact, rally and regroup is often the key to later strategic success.
The hundred days campaign contains both good and bad examples:
Blucher on the 16th/17th
Wellington on the 17th
Napoleon on the 18th/19th/20th
Grouchy on the 19th/20th
What aspects do we think contribute to a successful outcome, or lack of it?
neither Blücher nor Wellington did run away as such, Wellington had to retreat to keep the possibility open for re alignment with the Prussians in that way that Blücher could send support, and Blücher retreated in that way to enable this.
In my view this was very difficult to do so, to break away and to re group and turn the wheel by that - quite an achievement and this even by two independent army commanders, impressive.