There are occasions, such as Sadowa, where a General must play his last card.
There are others where with reinforcements in his rear, he can do better by saving his force and trying once again.

General Grant had an axiom that the best time for an advance was when you were utterly exhausted, for that was the moment when your enemy was probably utterly exhausted too, and of two such forces the attacker has the moral advantage.

Lord Methuen determined--and no doubt wisely--that it was no occasion for counsels of desperation.

His men were withdrawn--in some cases withdrew themselves--outside the range of the Boer guns, and next morning saw the whole force with bitter and humiliated hearts on their way back to their camp at Modder River.
The repulse of Magersfontein cost the British nearly a thousand men, killed, wounded, and missing, of which over seven hundred belonged to the Highlanders.

Fifty-seven officers had fallen in that brigade alone, including their Brigadier and Colonel Downman of the Gordons.