Distribution of count rates in 60 s bins for all IBIS observations of Cyg X-1, separated by state as determined following Grinberg et al. (2013). The bin width of the rate histogram is 80 cts s⁻¹. The count rates reached by the flares discussed in this paper are indicated within the bracket. At no time before the flares have rates of 350 cts s⁻¹ or higher been reached. Therefore, the flares by far represent the brightest observations ever seen with IBIS for Cyg X-1.