Imprecise Best System Chances

Attention has been paid to the prospects of the Best System Analysis (BSA) for yielding high-level chances, including statistical mechanical and special science chances. But a foundational worry about the BSA lurks: there don’t appear to be uniquely appropriate measures of the degree to which a system exhibits the theoretical virtues of simplicity, strength, and fit, nor a uniquely appropriate way of balancing the virtues in determining a best system. I argue that there’s a set systems for our world that are tied-for-best given the limits of precision of the notions of simplicity, strength, fit, and balance. Some of these systems entail different high-level chances. I argue that the Best System analyst should conclude that (some of) the chances for our world are imprecise.