1/2,783,947
which indicates they should solve about one block every month.
Every 32 hours actually (2,783,947 / 3600 / 24).
However their hashrate was much lower (like an order of magnitude lower) before the recent two blocks so it seems that fillippone had a point here:
Funnily enough I thought miners being the most rational agents, not easily fooled.
Not particularly rational if they start solo mining after someone else won a solo block.