What happened: Next Gen Stats measured the Seattle quarterback's spiral during training camp. The figure was featured in the current Hard Knocks installment.
Why it matters: The measurement gives Seattle a baseline for tracking Darnold's throwing mechanics through the preseason. Its value will ultimately depend on how the rotation translates into accuracy and production.
By the numbers: Darnold's spin rate is 639, the highest mark among NFL starters.
What to watch: Watch how Darnold's delivery and passing efficiency hold up in preseason work.