Robert Wells is a seasoned professional with over 35 years of experience across contracting and engineering, including roles as estimator, project manager, and risk analyst, specializing in electrical and instrumentation cost estimating worldwide. This presentation examines the rise and revision of AACE RP 41R-08, what was flawed in range estimating, and its lasting impact on practices like Monte Carlo modeling. It also highlights key distinctions between risk, contingency, accuracy, and cause-effect, while contrasting traditional range estimating with approaches based on correlation and orthogonality.