A sort of an adversary

We describe an efficient deterministic adversary that forces any comparison-based sorting algorithm to perform at least [MATH HERE] n log n comparisons. This improves on previous efficient adversaries of Atallah and Kosaraju (1981), Richards and Vaidya (1988), and of Brodal et al. (1996) that force any sorting algorithm to perform at least 1/2n log n comparisons.