The other day, I picked up the latest copy of the CAS’ journal, Variance and skipped to the back where Leigh Halliwell had an article. I hope that I’m well on record as being one of his biggest fans, but if not, let me remedy that now. Leigh Halliwell has done really tremendous stuff. He’s mathematically sophisticated, but addresses practical problems. I often struggle to keep up with his flurry of ideas and deft handling of the math, but once I (possibly) sort it out, it becomes embedded in my thinking.