Is it possible, within the freewill/determinism duality, to posit a third pole - namely 'chance' in which spontaneity is possible albeit within a set of limiting conditions?

Modern physics implies that some events are genuinely chancy, in away that undermines determinism: prior circumstances plus scientificlaws don't determine events like the decay of a radium atom, but onlyfix a probability for them. This might look as if it opens theway for 'strong free will', in the sense of allowing agents to affectthe world in a way that is unconstrained by prior circumatances. Butit isn't clear that this works. The idea that physical events all havetheir probabilities fixed by prior circumstances raises just as manyproblems for free will as determinism. The hope is presumablythat strongly free agents can make a difference to the occurrence ofchancy events, given that these events aren't determined. Butunfortunately this seems to be ruled out even by the weaker claim thatthe probabilities of chancy events are fixed by prior circumstances. Ifan act of my will, unconstrained by history, can make it more likelythat a radium atom will decay, say, then that event won't have...