This summer I am rereading one by one all of the Dick Francis books I have. I think there are eighteen out on shelves, and a similar number in boxes in the garage.
The guilty secret is that I think he is a much, much, better writer of crime fiction than Agatha Christie. After the Doctor Who episode about her, I took down "Death in the Clouds" to reread it and found it to be not just dated, not just as poorly written as a Jeffrey Archer, but badly plotted as well.
Dick Francis has created a world in which he can be absolutely confident as he writes and in which I can happily suspend my disbelief. Sheer brilliance!