But I think there is a low probability that will play out, not least as we have learnt from history.

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Not necessarily a better method, but an alternative method that will focus on probability of victory rather than the margin of victory based on resources in hand.

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But even the elite AAA rating currently held by Uncle Sam does not imply a zero probability of default for all time.

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Instead, to judge by the most comprehensive study on the reliability of forensic evidence to date, the error rate is more than 10% in five categories of analysis, including fiber, paint and body fluids. (Meaning: When the expert says specimen X matches source Y, there's a 10% probability he's wrong.) DNA and fingerprints are more reliable but still not foolproof.

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