Rectangle attack
A boomerang-style attack that counts many differential pairs instead of a single path, which can make some key guesses testable on paper.
Eli Biham, Orr Dunkelman and Nathan Keller presented the rectangle attack at Eurocrypt 2001. It builds on the boomerang idea: the cipher is split into two halves, and each half gets a differential. The difference is that a rectangle can contain many pairs with different intermediate values, so their probabilities are summed rather than requiring one specific path to succeed.
It has become a common tool against block ciphers with strong differentials. When you read a rectangle result, check how many rounds were actually attacked. Most published rectangle attacks cover reduced-round versions, not the full cipher.