the guy had been small , built like a bird , and reacher tended to assume that people opposite him on the physical spectrum were also opposite him on the personality spectrum , so that in place of his own placid nature he imagined the guy was all strung out and nervous , which might have meant that back there in the parking lot the guy 's heart was going as fast as 180 beats a minute , which meant those t-waves were coming around fast and furious , three times a second , which meant that the odds of hitting one of those crucial fifteen-millisecond windows ahead of a peak were about forty-five in a thousand , or a little better than one in twenty .