Complex sentence: Shusaku played with a handicap of two stones, but Gennan found that he was too strong, the game was left unfinished, and a new game was started with Shusaku just playing black.
Split into simpler sentences: Shusaku played with a handicap of two stones, but Gennan found that Shusaku was too strong, so he called off the game. A new game was started with Shusaku just playing black.