Balls on the lawn.
Baxter permutations and plane bipolar orientations.
Bender's generalized q-binominal Vandermonde convolution.
Bijections for hook pair identities.
Bijective proofs for Schur function identities which imply Dodgson's condensation formula and Plücker relations.
Bijective proofs of identities from colored binary trees.
Binary -words without the subword 1010. . . 10.