Sounds like conditioning isn't the issue! 4 to 5 miles, 5 times a week is more than most guys work their dogs, including mine! I have found as Springers get tired their range really drops .. from that perfect 10 to 20 yards, to almost sitting on your boot tops.

Confidence isn't the issue it sounds like either, some dogs just need to be close to their master, and stay close for support and encouragement. These dogs tend to start to range as confidence grows and with experience.

I would have to say you are experiencing the same thing I did with my Piper based on your comments. I lived in a busy area and when I would run I would keep her on a leash, when taking her to the park.. she was on a leash, when people and dogs came around she also was heeled. What all this "control" does though is enforce a VERY close working dog. You are essentially training your dog to stay at leash length to you when active out of the home. The Hickox tapes, I'm not familiar with but I am familiar with Hunt em up, so you obviously are training your dog in the field with real birds.

The solution that worked for me was to train the behavior I desired. It started in the summer taking the time to find exercise areas where I could "push" her out more. Removed all check cords during training and worked her on finding scented balls/retrieving at greater distances. I encouraged her through positive reinforcement to roam, often slowing down or stopping to create the desired seperation. I also agree with hand signal control would help, as a great way to get a dog to really hunt the thick stuff is to direct the actions of a close working dog. Take advantage of the proximity to cast your dog into the birdy looking cover. This allows you to move while the dog is in the cover letting them know seperation is ok and good. As far as the dog drifting behind you, in training if she gets behind you walk quickly away from her .. encouraging her to pass you, then slow down and praise her for getting out ahead. Make sharp turns when she's not paying attention .. forcing her to catch back up and get ahead .. she'll catch on quick, behind is not good.

Piper and I are in our 3rd year together and we have developed a routine now we have created through training and time afield. She quarters well slowly getting farther and farther out, at the point she's getting to the edge of where I want her I whistle her in and she comes in tight and we repeat. I like the control it gives me when I want her to work a particularly thick spot, and she likes checking back in often and knowing I'm watching how good she is doing. It also allows for great control when other dogs or hunters are encountered.

I'll end with, your dog is still VERY young. 18 months is just a pup, and her best hunting days are way ahead of her. The more hunting you do with her, the more you and her will learn to hunt together. Taking some time now while in the field to work on skills, will be well spent. Such as standing in a single spot for 5 minutes. She'll quickly cover that 5 to 10 yard arc.. and need to roam to hit new cover, a few atta girls and good girls when she leaves your boot tops will clue her in she's at the distance you want her to be.

Let me know how you make out and please send a pic.