Alan's outline isn't really probability in any meaningful sense of the term since all he is saying is something like 'if there are more guesses in favour of God then God becomes more likely' which is, quite frankly, nuts for a variety of reasons.
1. Probability requires a method that encompasses data that can be demonstrated to represent the various scenarios that are being described and compared.
2. The application of statistical tests is also essential, where this includes an estimation of random chance accounting for the outcomes of the method used , and again this requires an appropriate methodology that also involves data that is suitable for statistical testing.
3. The NT is anecdotal so it is difficult to see that it contains any data that is suited to statistical analysis in terms of assigning calculated weightings, which I assume is what the percentage approach Alan uses would involve.
Assuming that Alan isn't suggesting that looking at probability using a 'research methods' approach (which I confess was a major element of my education and career) then what is left seems to be something along the lines of 'what can reasonably be believed', which raises other problems if he is attempting to use probability in an argument in favour of the Christian God based on the NT narrative.
1. If all that is available are the anecdotal events as noted in the NT accounts, such as the 'empty tomb' that Alan often mentions, then it seems that Alan's approach to probability involves assuming that these events are actual historical facts.
2. Accepting these NT anecdotal claims as being factual would be an unjustified assumption unless there is a method being used that satisfactorily addresses the risks that these anecdotes might contain mistakes or lies: that they might is a risk that those claiming the NT accounts as factual would need to address, and to date there seems to be no method employed that has done so, and since assertion that the NT is 'inerrant' is clearly insufficient where levels of probability are being claimed.
3. Using anecdotal accounts as evidence that a supernatural event occurred is evidence only that this is what the people concerned claimed: but it isn't evidence that their claim is correct without a method that can be shown to confirm supernatural events independently of human testimony that may contain mistakes or lies. As yet no such method has been proposed that addresses this weakness.
The obvious conclusion is that attempts to claim God based on 'probability' arguments is nonsensical without an accompanying methodology, and since this would involve demonstrating a basis on which claimed supernatural events can be considered as being probability-apt then any claims that God is 'probable' is just so much white noise: as is often said, 'not even wrong'.
