Before revision:  A comparison with random networks of similar size and composition reveals that the yeast's cell-cycle regulation is exceptionally cooperative .
After revision:  A comparison with random networks of similar size and composition reveals that the yeast's cell-cycle regulation is wired to yield and exceptionally high level of coherent regulatory activity. We also investigate the mean degree of coherence as a function of the network size, connectivity and the fraction of repressory/activatory interactions .