Using Beersmith for the first time

I have got Beersmith for my iPad as I wanted to see if it could help produce better beer. I have one question though regarding batch sparging as I have also never done this before.

I am doing a 20L batch and here is what Beersmith is telling me.

- Mash in with 13.44L leave for an hour.
- Drain Mash tun
- add 18.53L

I always though with batch sparging you collected 2 equal amounts of wort in the boiler, Beersmith seems to be telling me to collect a little of the first running's than a lot of second running's?

Cheers
Nick

Read this:      http://www.beersmith.com/forum/index.php/topic,5140.0.html

and this:

dennybrew.com

Highly capable and adaptable systems often have lots of moving parts. BeerSmith is not an exception. It takes some time to get all the moving parts to work together well. Take your time and tweak it repeatedly until it gives you repeatable results.

Denny Conn's batch spargeing system is delightfully simple and can help you understand a significant part of what's happening inside BeerSmith.