Left 4 Dead 2

After trying numerous times, using a second controller in system link, AND incapping the sacrificed guy over twice and not getting the achievement, i tried boosting it with a buddy...So to make this as easy as possible boost with one friend. One is all you need. Make sure its on local server and on the Port.

The person getting the achievement actually has to do the least amount of work. They have to wait, while the survivor player activates all the generators. The Infected player will be a tank 3 times now. All they have to do is go to the front of the bridge (great meeting place for this) and get killed as quickly as possible. This way the CPU does not take over the tank. Once the bridge comes down, this is where the important part comes in. The Infected player (person getting the achievement) will now spawn through all the special infected. You are going to want to be either a Hunter or a Charger. If you spawn as something else, get killed. Make sure the survivor player does not push the button until so. Once you are able to spawn as a either a charger or hunter. The survivor pushes the button

NOW you have a window here of about less than 2 minutes.. There is a little alley way to the right of the bridge (behind the turret gun) This is where they infected player will hang out. The survivor should run and jump over the gun, then once on the floor turn right and go into this alley way, and now the infected player can either Charge (charger) right into the survivor or pounce (hunter) no other infected will be in this area interfering while you incap them. My buddy and I got these on the first shot. I was a charger and he used a hunter.

Hope this helps everyone

Remember 5 Quick Tips...
1. LOCAL SERVER ONLY
2. Boost with a friend, dont try this by yourself
3. When spawned as the tank, get killed as quickly as possible
4. Charger or Hunter, EVERYONE ELSE SUCKS..(maybe not the smoker, but dont test your luck)
5. Alleyway to the right of the bridge

ACHIEVEMENT UNLOCKED !

The Sacriffizle achievement on left for dead 2. you have the solution for the chievo here: read the other solution to follow it through text.
Credit to MrSmugz

You can get this in split screen, but it is easier to do with another player. It’s even easier to do with four players on the infected team as then you get no infected bots which can ruin the achievement.

Make sure you choose local server and The Sacrifice level The Port.

Make sure the infected team do not spawn until they are forced to spawn as a tank. This is very important as when they take over control of the tank, the special that they were becomes a bot and can either ruin the achievement or just make it a lot harder for you.

Start up the generators one by one and then camp at the entrance to the bridge. Take out the zombies and specials that come to you.

When the tank comes as a result of starting the generators, have the tank go to the bridge and go to the little alleyway at the left. From here they can walk up a ladder into the sea and then instantly kill themselves, making the achievement quicker to achieve.

When the final tanks come, you'll either have to dodge the other tanks until the person who is getting the achievement is a tank, or if you are playing with more people on the infected team you can just wait for the person getting the achievement to become a tank.

Once that person is a tank, go next to some of the cars near the bridge and wait for the tank to knock a car into you.

Cars are instant incaps and the person getting the achievement should get the 50G.