One way to identify counterfactually-excellent researchers would be to compare the magnitude of their “greatest achievement” and secondary discoveries, because the credit that parade leaders get is often useful for propagating their future success and the people who do more with that boost are the ones who should be given extra credit for originality (their idea) as opposed to novelty (their idea first). Newton and Leibniz both had remarkably successful and diverse achievements, which suggests that they were relatively high in counterfactual impact in most (if not all) of those fields. Another approach would consider how many people or approaches to a problem had tried and failed to solve it: crediting the zeitgeist rather than Newton and/or Leibniz specifically seems to miss a critical question, namely that if neither of them solved it, would it have taken an additional year, or more like 10 to 50? In their case, we have a proxy to an answer: ideas took months or years to spread at all beyond the “centers of discovery” at the time, and so although they clearly took only a few months or years to compete for the prize of first (and a few decades to argue over it), we can relatively safely conjecture that whichever anonymous contender is third in the running is likely to have been behind on at least that timescale. That should be considered in contrast to Andrew Wiles, whose proof of Rermat’s Last Theorem was efficiently and immediately published (and patched as needed) This is also important because other and in particular later luminaries of the field (e.g. Mengoli, Mercator, various Bernoullis, Euler, etc.) might not have had the vocabulary necessary to make as many discoveries as quickly as they did or communicate those discoveries as effectively if not for Newton & Leibniz’s timely contributions.
One way to identify counterfactually-excellent researchers would be to compare the magnitude of their “greatest achievement” and secondary discoveries, because the credit that parade leaders get is often useful for propagating their future success and the people who do more with that boost are the ones who should be given extra credit for originality (their idea) as opposed to novelty (their idea first). Newton and Leibniz both had remarkably successful and diverse achievements, which suggests that they were relatively high in counterfactual impact in most (if not all) of those fields. Another approach would consider how many people or approaches to a problem had tried and failed to solve it: crediting the zeitgeist rather than Newton and/or Leibniz specifically seems to miss a critical question, namely that if neither of them solved it, would it have taken an additional year, or more like 10 to 50? In their case, we have a proxy to an answer: ideas took months or years to spread at all beyond the “centers of discovery” at the time, and so although they clearly took only a few months or years to compete for the prize of first (and a few decades to argue over it), we can relatively safely conjecture that whichever anonymous contender is third in the running is likely to have been behind on at least that timescale. That should be considered in contrast to Andrew Wiles, whose proof of Rermat’s Last Theorem was efficiently and immediately published (and patched as needed) This is also important because other and in particular later luminaries of the field (e.g. Mengoli, Mercator, various Bernoullis, Euler, etc.) might not have had the vocabulary necessary to make as many discoveries as quickly as they did or communicate those discoveries as effectively if not for Newton & Leibniz’s timely contributions.