While Cliodynamics uses quantified information of the past to chart the future, most alternative histories seem to be based on supposition rather than statistics. In a Financial Times piece highlighting the best books of the summer, conservative British politician Kwasi Kwarteng suggests what sounds like a very good volume which focuses on counterfactuals:

“I have enjoyed many books this year but one that stood out, partly because of its unusual nature, was Altered Pasts: Counterfactuals in History (Little, Brown) by Richard J Evans. Counterfactuals are the kind of guessing game we play when we wonder what would have happened if, say, Napoleon had won the battle of Waterloo. Evans’s book reveals how much of our modern thinking about history is dominated by counterfactuals. For example, in the last 20 years, many novels have featured lurid depictions of a Britain conquered by the Nazis. Altered Pasts is a good read, which stimulates further reflection about the nature of history.”