Like classic online Solitaire, not all Spider Solitaire hands are winnable. We estimate a 55-65% win rate for 1-suit Spider Solitaire, 20-25% for 2-suit, and 5-10% for 4-suit.The more suits involved, the more challenging the game. At Solitairea.com, we allow users to play winnable games to avoid getting stuck in an unwinnable situation.