First round you are set up with another random shooter. You shoot a round of 28 blocks. one shooter shoots even targets first while the other shoots the odd targets first. You can get a maximum of two shots however if the block is knocked over that ends the round and the archer marks down an x and the target is closed.
After all the archers have shot the score cards are added up and the next round they will match up the highest score to the lowest score. So an archer that hit 28 targets would be matched to an archer that hit zero targets. Often the highest shooter would get a "bye" which means there wasn't enough archers to match him up with.
Second round you shoot 14 targets and all the winners would stay in A class while all losers will go to B class.
3rd round losers go to C class and in the from then on whoever loses is eliminated from the competition.