In this week's episode Patrick and Greg explore Sewall Wright's path tracing rules as an alternative to covariance and matrix algebra, including how the rules work and the tremendous insights they can provide toward understanding a model. Along the way they also discuss the Unabomber, Crate & Barrel, grocery lane profiling, tedious as poop, throwing dead cats, senior animal husbandman, using your fingers, creepy guy in an alley, sweat pants vs. suits of armor, getaway car drivers, hold my Guinea pig, chalkboard contests, Western Kansas, and getting tased.