The Back-to-Back (B2B) bonus is a powerful mechanic that rewards you for performing consecutive 'special' line clears. A special clear is defined as a Tetris (4 lines) or any T-Spin (Single, Double, or Triple). When you perform a special clear, and your very next clear is also a special clear, you receive a B2B bonus, which adds an extra line of garbage to your attack. This bonus continues to stack as long as you maintain the chain of special clears. For example, a Tetris followed by another Tetris will send 4 + 1 = 5 lines of garbage for the second Tetris. A T-Spin Double followed by a Tetris will send 4 + 1 = 5 lines for the Tetris. The B2B bonus is indicated by a small flame icon next to your score. Maintaining a B2B chain is a hallmark of advanced players and can significantly increase your offensive output. Always strive to follow up a Tetris or T-Spin with another special clear if possible. This requires careful planning of your stack and efficient use of your Hold queue to save 'I' and 'T' Tetriminos. Breaking the chain with a single, double, or triple clear will reset the B2B bonus.
