Stump pull can cause a degrade of log value if allowed to occur. Improper falling, most commonly not leaving a deep enough undercut, or inadvertently leaving a "dutchman", often will lead to excessive stump pull. Stump pull is equivalent to pulling the heart out of a ripe watermelon.

Below, a large sugar pine (Pinus lambertiana) is just going off the stump. Notice the little to no stump pull left on the stump. An excellent falling job.