Here is my method,
Here are all the LB heroes I have.
Note: I do not gurantee ANYTHING! If you have missed a collection of LBs then the only thing to do is open LBs by the 10s that also means disreguard everything after this notice.
My System for opening LBs. I swear it has worked since the OS collection (That is when I learned it)
Here are the steps as followed as well as detailed instructions.
When I get LBs I don't just open 10 at a time I also open singles but in a certain way,
If I get 4 LBs or less I open all 4 but if I get 6 or 9 more then I open the LBs until I get to 5 then I farm up to 10.
5 LBs means it's your choice whether to open all, a few (I recommend NOT opening a few. Go all or nothing) or none
Less then 5. Open all
More then 5 but less then 9. Open LBs UNTIL you get back to 5 then farm to 10.
10 plus extras means you open 10 then open the rest (If you have 14 then open 10 followed by 4 singles)
In Spec Ops getting the LBs is easy however this method is a bit hard when your doing PvP LBs. I barely scrapped the last cover of Juggernaut right after the tournament ended. I opened a single LB and the final cover was mines.
For PvP LBs just open 10 at a time. But if you get anymore then 10 then open the extras, so if you get 13 open 10 then 3.
I have every LB hero (Except Satana because I didn't even try for her. Don't ask)
Most of the Thane covers I got from singles I got like 5 covers from opening 1 LB.
That's the system ain't nothing to it.