Yup, I leave a 20 footer to drag while they run around. It's usually in a mostly fenced place though cause I'm really paranoid. Maybe you can find a really light rope to leave on Claire (although.. light for Claire might be hard to find LOL). That way, you'd be able to grab her if she decides to bolt, she'll think she's totally off leash and you'll get an idea on how good she is off leash.