Red Dead Redemption

7 saloons total, located in:

-Armadillo
-Thieves Landing
-Rathskeller Fork
-Escalera
-Chuparosa
-Casa Madrugada
-Blackwater

In each saloon, switch your weapon to fists and do that passive-aggressive thing where you kind of drunkenly stumble into an NPC until they fall over. They will get back up, but they won't be happy about it. Beat them unconscious with the right trigger and move on to the next saloon. Note that knockouts don't last very long in this game, and they'll stand up quite quickly, but that's okay. You don't need to beat them to death.

It's probably best to only fight one barfly at a time, if possible.

Edit from STLfan2468: Make sure to get the knockout INSIDE the bar, not just outside the doors, for it to count.

Edit from various comments: Make sure you save after you knock someone out in each saloon (if you die before getting an autosave, the KO won't count). You can quickly save by using one of the horse deeds from your inventory at any time.

It takes roughly 8-9 landed blows to knock someone out.

Be warned that as soon as you start fighting with one person, their friends will all jump in too. Try to pick out lone patrons to pick a fight with, but when out numbered just remember you can either try to bottleneck the group so that only one member is in range (behind the bar can work, as can corners and staircases at times), or kill the friends, as only one knock out is needed to tick off a saloon.

Another issue players might have is with patrons not looking for a fight. As soon as you hit them, they will attempt to run, and if you don't knock them out before they get out of the saloon, it doesn't count. If everyone in the saloon runs, leaving the place empty, just go outside and pick a fight, bringing the fight back inside. Characters aggressive to Marston will follow him when engaged in a fight, and as long as the knock out occurs inside the saloon, it counts.

Although fairly easy to knock out someone, if they start blocking, they are going to keep blocking until they see an opening. If your target starts blocking your punches, block until they throw one, then continue beating them up.

After equipping your fists in the weapon selection screen and readying your fists with LT, you can punch with RT, block by holding RB, or dodge in any direction by pressing X and moving in the direction.

There are 7 towns with saloons in them, and not all of them will be accessible until you have competed the second chapter.

In New Austin:
Armadillo
Rathskeller Fork
Thieves' Landing

In Nuevo Paraiso:
Casa Madrugada
Chuparosa
Escalera

In West Elizabeth
Blackwater

If you knock someone out, and consequently die, you lose that check, so as soon as you knock someone out, try to save (sleep) or quick-save (completing a random encounter, using a horse deed, etc.)

To do this, you must knock a person out in every bar in the game. First of all, in order to knock someone out, unequip your weapons, and just punch them until they fall onto the ground. Th bars are located in these places:
New Austin
-Armadillo
-Rathskeller Fork
-Thieve's Landing
Nuevo Paraiso
-Casa Madrugada
-Chuparosa
-Escalera
West Elizabeth
-Blackwater

Cheers!

There are 7 saloons in the game in which you need to knock someone out. In terms of saving the most time (travelling manually) or money (using a stagecoach), here's my recommended order:

Blackwater
Thieves' Landing
Armadillo
Rathskeller Fork
Escalera
Chuparosa
Casa Madrugada

I found the easiest tactic was to simply target the barman. Nobody jumps in to help him, and you can usually block his exit at the bar. He does always try to run but as long as you time your punches correctly, he's not going anywhere.

If you target someone with a hat, you can tell they've been KO'd because their hat flies off before they fall over. You're free to leave the bar as soon as the hat flies - they're on their way down.

If you can't find anyone inside the bar who looks like an easy target (I assume the barman has got away), you can try going into the street and hitting someone once before running back to the bar and hoping they follow you. I did this in Armadillo because it was full of Walton's Gang, and they're to be avoided.

Always make sure to sleep/save before moving on to the next town as you never know what might be waiting when you get to the next place. This is easily done when you have completed the game and own all the properties, many of which are located inside the bar itself.

There are 7 saloons in the game in which you need to knock someone out. In terms of saving the most time (travelling manually) or money (using a stagecoach), here's my recommended order:

Blackwater
Thieves' Landing
Armadillo
Rathskeller Fork
Escalera
Chuparosa
Casa Madrugada

I found the easiest tactic was to simply target the barman. Nobody jumps in to help him, and you can usually block his exit at the bar. He does always try to run but as long as you time your punches correctly, he's not going anywhere.

If you target someone with a hat, you can tell they've been KO'd because their hat flies off before they fall over. You're free to leave the bar as soon as the hat flies - they're on their way down.

If you can't find anyone inside the bar who looks like an easy target (I assume the barman has got away), you can try going into the street and hitting someone once before running back to the bar and hoping they follow you. I did this in Armadillo because it was full of Walton's Gang, and they're to be avoided.

Always make sure to sleep/save before moving on to the next town as you never know what might be waiting when you get to the next place. This is easily done when you have completed the game and own all the properties, many of which are located inside the bar itself.