First of all don use that 3 on 1 off technique that worked on blops it won't work in mw3. What your doing is lagging out the possibility of getting host. You can't lag a host migration either. Stick with 3 or 4 seconds of lag to get host/matched players. Here is my technique and it works almost flawlessly for me. I use no router I'm plugged strait into modem.
1. Select game type / high player count games work best Dom, groundwar, tdm
2. Watch top left of screen it will start by saying searching for 7 more players. This is when you hit the lagswitch and hold for 3 seconds then release. If matched players appear then change to names of players. If it goes strait to names backout. If it starts to do the % of games thing backout and repeat step 1.
3. Wait till room fills up and host migration happens. You can't lag the migration you are at the mercy of probability. But because you forced the game to start you as host the likelihood of keeping host increases expodetialy.
4. I haven't figured out how to tell if your host before the game starts. But a real good indicator is your name will be at the top or at least in the top 3. Now this is just theory at this point but seems to be the case the majority of the time.
Once the game starts loading select your weapon immediately, I don't mean scrol thru your classes then choose. But select the default weapon and countdowns if 12 seconds means host. This is absolute. Sometimes it will be 13 seconds but as the timer hits 12 you will notice the screen will glitch/focus weird. Anything 10 or lower is not host.
After the game has ended dosent matter about host migration you will keep host unless the scores change to zero. This is absolute.
If you are on ps3 mp me your I'd and I'll Inc and help via playstaion chat
---------- Post added at 09:14 AM ---------- Previous post was at 09:09 AM ----------
Also if you get into a game and are not the host you can hit lagswitch until you get disconected. This will send you back lobby and will not give you a loss for quitting.