Load Balance Electric Main Panel
What matters is your actual draw, not the numbers on the breakers.

So for instance, if you have 5 circuits of bathroom, bedroom, laundry room, and kitchen... And then 5 circuits of Bitcoin miner that run at 15.9A 24x7... You don't want to put the miners on one leg and the household load on the other.  The 2 kitchen circuits are rarely used, for instance, so they don't balance the miners.  

On the other hand, if you have a gaming rig circuit and an air conditioner circuit  to keep the room bearable, thatd be a pretty good balance since they'd  run together.  

It isn't left and right, unless it's PushMatic

Most modern panels arrange like this.