Hi Dave,
New to the period and forum myself and I haven't even played a game with my BLB rules yet.I'm busy building my Marlburian British army and just reading the rules over and over again and like anything new it takes time to understand the mechanics of how they work.
Infantry Charges and Melee Page 20
It is confusing the way it has been worded, but the way I understand it 3 turns/rounds of combat is the maximum number any one battalion can fight unless reinforced.
After each round of combat the loser being the battalion that received the most casualties must test there morale Page 23 Testing Infantry Morale see 7th circumstance - Lost melee and pushed back this turn.
So with bad luck the losing battalion may not even be there to fight a second or third round.
Again on Page 20 Raw Troops break/rout automatically on first push back,
Drilled Troops on second push back, Elite on third, and Guards on forth consecutive push back.
All troops in melee are disordered after their first round of combat and anyone joining a melee are automatically disordered.
Next again on Page 20 you need to understand that infantry can only Charge shaken or disordered infantry or a defended obstacle, except if Tribal infantry who can charge anything.
Standing and Firing at Chargers is a choice infantry may make when being charged themselves, these casualties count towards the casualty result when working out the overall results of a melee.They may also stop cavalry charging home.
Just keep reading the rules over and over again and the mechanics of them should fall into place.
Hope this helps.............Ray.