hi every one ! 
I've discovered a way to save the rank stats in bo1
1 - find game = game tactical
2 - Suicide 6 times Press START to watch to watch xp line
3 - dont leave the game until you get the host
4- after you get the host you can leave the game you will get lvl 50
6- play a ( Team Deathmatch ) 1 game don't leave the game until you finish the game
7- insert prestige and get to the main menu
8- go back multiplayer you will see lvl 50 is saved
you need to make it until you get prestige 14 \ 15 as you like
youtube
I've discovered a way to save the rank stats in bo1
1 - find game = game tactical
2 - Suicide 6 times Press START to watch to watch xp line
3 - dont leave the game until you get the host
4- after you get the host you can leave the game you will get lvl 50
6- play a ( Team Deathmatch ) 1 game don't leave the game until you finish the game
7- insert prestige and get to the main menu
8- go back multiplayer you will see lvl 50 is saved
you need to make it until you get prestige 14 \ 15 as you like
youtube