one thing should be known about BG's and honestly its what matters the rest is on you 

• they are not here to make your army bigger 

now go ahead and find a use for them that suits your gameplay best :))

My Lords,

Lord Euclus,

you're right. Players are choosing their tournament rewards although they should be careful. Even in tournaments they will invest more than expected as reward. 

Those are BG stages, they are calculated in my case to make progression in BG a lot easier, without draining your army. 

Stage one will begin with at level 1-11, then end at 11-40

Is best to do BG from that level, clear them have your reward and train 15-20% more of your army. Once you have 20% more in troops, you can then progress further to level 65.

it is also tailored with hero equipment, building upgrades, lost arts ect. So by the time you reach level 65 BG, or stage two you should have already discovered all your bestiality lost arts, and you will start to receive beast hero equipment at stage two.

so according to Hero equipment and lost arts it will be like these

Stage 1 A( level 1-11). at these stage you are a new player can only build pikes and archers. 

Stage 1 C (level 20-30) you have discovered pathfinders lost arts, at these stage you will be receiving cavalry Hero equipment

stage 2 B, (level 62-65), you have discovered all lost arts your resource production building are at level 20+. 

I Found these in Pirate server. I am still looking for the source, as it was quoted by another poster.

''We don’t share the exact algorithm for the feature, but here’s the basic outline: every time you attack or defend a [prize], your unit losses are totalled up according to each unit’s price in [Rum, Gold, Lumber]. This running total is your Payout Number. When you get payout from a [Prize], the spread, number, and type of Units or Resources you receive are randomly allocated as measured in resources based on that total.

The longer you go without receiving a payout, the higher your Payout Number total is becoming and the bigger your eventual reward will be (that's if you continue to bank). Now, there are also some randomized triggers when running this calculation – first, it does a “spin” to see if this infestation will pay out this time, or just keep adding to your Payout Number. Depending on how this spin goes, it’s possible to go extremely long periods without getting a payout (even though your Payout Number is still growing over time). This is especially true if you've received big payouts on higher-level [Prizes] and then go back to hitting low-level ones.

The payout frequency is a little higher for the [prize] that pop up directly on the left side of your screen, but those require hitting consecutively higher [prizes] each time. Sometimes you can also “spin” and hit a superbonus, which will trigger a payout worth more than your total investment, but those don’t pop up much.

The biggest misconception is that regular [prizes] each have their own discrete payout amount. I know it often seems like we’re laughing maniacally to ourselves as we change each [Prize] Level’s payouts every week to confound everyone – this isn't true. It doesn't work that way.

The payouts are based on your collective Payout Number; the last time you triggered a payout, and how many Unit losses you've suffered in the meantime. Treat it like Black Jack; play with a long view, don’t bet everything you have, and quit when you’re ahead. It can be frustrating, but senior players have experimented with different strategies and gotten pretty good results. Ask around, but be prepared to lose a lot of troops to get there – don’t commit anything you’re not ready or able to lose without being hamstrung.

Some advice: take advantage of Global Mission events to “double dip” on your investment. Also don’t forget to include the XP, and Ranking Points, ranking awards, Achievement Bonuses, and other freebies you’re getting from taking on the Infestations.

Also, if you want a sure bet, don’t forget about the Campaign [Prizes]. Each one of these has a fixed payout in [Brethren] units that you can view before deciding whether or not to run the mission – plus they all have a pretty cool storyline and audio content, but the higher ones get really, really tough.

In the coming months we’re planning to experiment with the payout frequency algorithm to make it a little less discouraging from the player end, so standby for future announcements.''