Adversary model

In computer science, an online algorithm measures its competitiveness against different adversary models.

For randomized online algorithms competitiveness can depend upon the adversary model used.

This adversary knows everything, even the random number generator.

This adversary is so strong that randomization does not help against it.

From S. Ben-David, A. Borodin, R. Karp, G. Tardos, A. Wigderson we have: