I'd say the depths of his stupidity have yet to be plumbed, and yours is comin' up fast on the inside turn

I'd say the depths of his stupidity have yet to be plumbed, and yours is comin' up fast on the inside turn

The phrase "I'd say the depths of his stupidity have yet to be plumbed, and yours is comin' up fast on the inside turn" is a colorful and evocative way of expressing the idea that someone's level of foolishness is still not fully understood or appreciated, and that another person's foolishness is quickly catching up. The use of the metaphor of plumbing depths and racing on a turn adds a sense of urgency and competition to the statement.