I purchased 17 runners for herding. Keep in mind that once they get to laying age you should only be practicing with the mallards so if you order straight run get more than you think you'll need. I ended up with about a perfect split, 10 boys and 7 girls so I have a laying flock and still have enough Mallards to work in two groups.
I thought all the ducks I saw at trials were Runners, after I purchased them I found out that at least in my area they are Runner crosses, usually with something like a Rouen, approx 3/4 Runner 1/4 something else. This is done to make a less flighty duck, without loosing the lack of flight. They can fly, they just tend not to and when they do it's not very high or long. I haven't found mine to be excessively flighty so I don't know if I'll keep them pure or go ahead and mix in something else, they can definitely be flighty but with my dog that works well, she has to practice TINY movements and not putting to much pressure on them.
I thought all the ducks I saw at trials were Runners, after I purchased them I found out that at least in my area they are Runner crosses, usually with something like a Rouen, approx 3/4 Runner 1/4 something else. This is done to make a less flighty duck, without loosing the lack of flight. They can fly, they just tend not to and when they do it's not very high or long. I haven't found mine to be excessively flighty so I don't know if I'll keep them pure or go ahead and mix in something else, they can definitely be flighty but with my dog that works well, she has to practice TINY movements and not putting to much pressure on them.