POSSIBLE SPOILER ALERT FOR GAME OF THRONES SEASON 6 EPISODE 9
Jon has been gathering an army along with Sansa and Ser Davos Seaworth to try to take back Winterfell from the Boltons. We have constantly heard that they don't have enough men and it's true, they are vastly outnumbered.
In the promo for episode 9, entitled 'Battle of The Bastards', we see that the Stark's army is much smaller than the Bolton's and we hear Jon say "Battles have been won against greater odds"
How can they win?
We know that wildlings are vicious warriors and they have a f**king giant on their side. The wildlings will take at least 10 people with them if they go down.
Then there's the northern families. The Mormonts have given Jon 62 men to fight with and a few other houses have contributed but it's not a lot.
One reddit user was able to figure out was the letter Sansa wrote last epsiode contained and the text in it seemed to point to Lord Petyr Baelish.
Baelish is the step-father of Sansa's cousin Robin Arryn and he has command over the Knights of the Vale. It's not likely that the Knights of the Vale will be able to get to Winterfell beofre the battle starts. Instead I think there'll be a 'Battle of Helmsdeep' situation like in 'Lord of the Rings: The Two Towers'
When the battle seems lost and everyone is dead (except for Jon and Davos of course) the knight's of the Vale will ride over the hill and deal a heavy blow to the Bolton army. This will give Jon a chance to maybe find Ramsay and kill him.
'Battle of the Bastards' is going to be the big battle episode of the season. Finale is entitled 'The Winds of Winter' which is also the name of the sixth book which is yet to be released. 'The Winds of Winter' is probably a refernece to the White Walkers and that they're bringing the winds of winter.
In the promo for episode 9 we don't we anyone outside of the Stark storyline, which probably means there won't be a lot of Stark in the finale. Since we haven't seen Bran, Meera and Benjen since episode 6 we will likely see more of them.