White could not avoid losing a piece. He could have played 1. d7 and capture the piece on h4 with his next move, but, because of the GIPF on e7, he would have recycled one piece less than Black. So, he let Black go one more piece ahead, but makes sure to have one extra pieces in reserve. Black must play 1. … g1-g5;x and finds himself with his pieces scattered all over the board. White plays 2. b1-f4;x and makes sure that Black will be the first to run out of pieces. That is why 1. c1-c3 or a3-c1 wouldn’t have been good enough, because White needs the piece on b3 to prevent Black from making a capture on the a4-h1 line. If Black plays 2. … a4-d4, White answers with 3. a2-d5 and will have no problems to win the game from here: f3 is too isolated and f7 and h4 are separated by white pieces.