@Benkura:
When my first B was young, we took him to a field to run him loose. He was great at recall (he also had 2 other breeds to teach him) and we even let him off when we went to beaches etc. What I have discovered is that Bs are fine at recall when they are young - maybe up to 18 months or more - then they get wise and cannot be trusted.
This has been my experience too. It works until it doesn't. My dogs are off lead to do agility and lure coursing, but there is something for them to focus on. I would never trust my dogs off lead on a hike where there are lots of critters for them to encounter/chase. Of course where I am, a hike may include cougars, coyotes, snakes (okay not now with all the snow on the ground), and rabid skunks (yes, that was on the news last night). Not to mention other people/dogs. There are some off-lead dog parks in the area, but with 4 dogs and 5 acres to myself, I don't really feel the need to go there.
I would say if the OP is interested in training a superb recall, get a booklet/video called Really Reliable Recall. You can find it at dogwise.com. The author has trained Afghans and whippets using this system. AND practice, practice, practice those recalls (good idea for everyone!!)