1.f4 is the Bird opening. It was played by Henry Bird. He wanted to leave the mainstream and create new original positions. He liked a setup with b3 and Bb2. The Polar Bear System (PBS) was played with the same intention. To leave the trodden theory paths and enter new undiscovered terrain. The system starts with a fianchetto of the Kings bishop after 1.f4, d5. PBS players want to enter interesting and original positions where it is difficult for Black to play for a flat equality. The book is for club players but also professionals can get inspiration. The book contains both volume 1 & volume 2. Grandmaster in chess. Henrik Danielsen www.polarbearsystem.com