OK. So Jon Snow, hardened general and leader of men, brings like 3500 men to fight Ramsay Bolton’s 6k or so. Snow has little cavalry, and his army relies on a core of elite Wildling light infantry. The Boltons have a classic Alexandrine combined arms force: a strong cavalry contingent, good missile troops, and heavy pikemen.
Against such a daunting army, Snow has few options. The logical move would be to accept aid from Littlefinger in advance of the battle, or at the very least for Sansa to TELL Jon that there’s a few thousand knights riding to their aid. But let’s set that aside for the moment.
Even if we accept Snow’s pre-battle assertion that the Bolton soldiers are demoralized (an assertion for which we see ZERO evidence in the episode), open combat with the above order of battle is suicide. Snow must play to his advantages: wage a guerrilla campaign aimed at drawing the Bolton forces out of Winterfell, lure them into favorable terrain that mitigates the Bolton cavalry advantage (after all, there’s no shortage of forests or badlands in the North), and use the speed and flexibility of his light infantry to spring an ambush.
Instead, of course, Jon Snow the idiot meets the Boltons on OPEN GROUND and JUST FUCKING CHARGES THEM HEAD-ON, playing perfectly to Ramsay’s advantages and completely neutralizing his own. He keeps his cavalry within the main body of infantry without deploying them to the flanks to fend off the Bolton horse or, say, the units of spearmen which he just watches encircle his forces. He bunches up his troops instead of creating a wide, thin line to envelop the Bolton army. He does not hide reserve forces in the woods or deploy them in the flanks. His missile troops JUST STAND AND WATCH instead of advancing to fire on Ramsay’s archers or attacking the rear of the encircling spear troop. Also, hey, you have a FUCKING GIANT, JON, MAYBE THINK ABOUT HOW THAT MIGHT BE USEFUL? Finally, he charges out ahead of his own forces to rescue his mentally handicapped brother, who runs in a straight line away from a man with a bow.
The Knights of the Vale seize victory from the jaws of defeat, admirably rolling up the Bolton flank, but not in time to save Jon Snow from going down as the worst general in the history of premium cable. Kudos to Ramsay for a well-executed battle plan, but really, he could have done whatever he wanted and still out-generaled the Stark bastard and his crack military council of George Custer, Douglas Haig, and Fightin’ Joe Hooker.