> A Ballistic Monte Carlo Approximation of π
>>We compute a Monte Carlo approximation of π using importance sampling with shots coming out of a Mossberg 500 pump-action shotgun as the proposal distribution.
Definitely you can compute pi by scanning a uniform grid in a square and checking how much ends up in the quarter-circle. But with these stats tricks applied, mere 10k points give the author very good approximation, beating 22/7 30% of the time. Scanning a 100x100 grid will give a much coarser approximation, I suppose.