Balance of Probabilities

In Lancaster v Blackwell Colliery Co Ltd (1919), 89 LJKB 609 Lord Birkenhead LC said at p.611:

If the facts proved give rise to conflicting inferences of equal degrees of probability, so that the choice between them is a mere matter of conjecture, then, of course, the applicant fails to prove his case, because it is plain that the onus in these matters is upon him. But where the known facts are not equally consistent, but there is ground for comparing and balancing probabilities, as to their respective value, and a reasonable man might hold that the conclusion for which the applicant contends is the more probable, then the arbitrator is justified in drawing an inference in his favour.

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