Application of the statistical methods of Gough (1981, 1983) to the epochs of sunspot minima and maxima of 24 activity cycles between 1712 and 1976. Upper panel: (Corrected) Original method of Gough (1981). Lower panel: modified method (Gough 1983). In both panels, the symbols show the ratio as a function of N (number of cycles in the data segments) for cycle minima (squares) and maxima (rhombs). The lines indicate the ratio of the expectation values, for case R (random walk of phase; blue curve) and case C (clock synchronization; red curve), respectively. The shaded areas show one-sided 68% (p₆₈) and 95% (p₉₅) percentiles determined from 10 000 Monte-Carlo simulations for each case. In both panels, the data points align well with the curve corresponding to case R (random walk) while case C (synchronization) is rejected at a confidence level of at least 95%.