How can I exploit this shuffle ?

I have discovered a blackjack game which has a very simple one pass shuffle. Its a six deck game with reasonable rules. The game is played down to between one and a half and two remaining decks before being shuffled.

The shuffle is as follows,

The dealer breaks the six decks into two piles of three picks up a pile of cards mabey about 40 or so, of each pile and the rifles them together into a new pile. This is repeated until a new deck is created this is the cut by a player and the game continues.
Thats it !
Only one pass.

This sould give you the general idea.

START SHUFFLE END RESULT
1
2
3 ---> --->
4 1 4 3+6
5 2 5 2+5
6 3 6 1+4

I've never bothered with any shuffle tracking before. Im guessing there are probably some pretty sophisticated sequencing and tracking methods around.

Can anybody help me out or point me in the right direction ?

All advice apprecicated.