The Monte Carlo financial planning tool aims to take the guesswork out of long-term planning. While most financial planners would agree with the old adage that long-term financial planning is a crap shoot, the Monte Carlo simulation is supposed to help planners more accurately project the odds of being able to meet their financial planning goals. "This process takes out some the guesswork by helping us determine the probability of accomplishing our stated objectives," says Irvine, Calif., planner Joel Goldhirsh.