New opening ideas are often the product of working with a computer in today's digital age, with the battles shaping the forefront of chess theory often taking place in engine vs. engine matches on Playchess.com . With the Slav Powerbook 2011 you get the best of both worlds - 7,000 master games played as recently as January 2011 and 11,500 high class Slav games straight from the Playchess.com Engine room to make a gigantic and up to the minute position tree !