Before we got Lilly.....Lola had a reliable recall.  This was achieved through check cord training in the back yard and keeping treats with me to give whenever she came on command.  Now its like Lola has simply forgot what she learned.  She won't run out of sight but she doesn't come when called nearly as reliably as she used to.  She still watches where I am and will check in often but I don't like that she has lost her recall.  The problem is that in a controlled situation ( our yard ) she comes 100% of the time, so i'm passed the controlled area stage (Lilly is passed that point too).  Anyone have any suggestions as to how to manage two pups on check cords in open fields?  They are each 50 feet in length (too long?).  Lilly is starting to get the idea but I don't want Lola's recent bad habits to rub off on her before she gets too old.  I want to be able to let them run and trust that they'll come each and every time no matter what.

I agree with what pixie has posted, but I usually end up using an ecollar (allows me to reach out and touch the dog when they don't mind) to correct the problem you are having.  There are a bunch of other posts regarding how to do this, so I am not going to repeat it here, but if you have specific questions, let me know.

It usually only takes one or two times for the dog to get it, and the problem vanishes.

It sounds like the place to overlay the ecollar.

Always reward when they come.  In the dogs mind, they are trying to please you if they come out of jealousy.  You never want them to associate come with anything other than good things happen, even if they come when not called.

I agree you should try all options before going to the ecollar. Just wanted to put it out there though as it does work.  I never needed it with Belle, but never would have gotten a reliable recall with Halo without the ecollar.  I used it on Ringo as I wanted to get him off leash faster for hikes and wanted that recall to be reliable before I let him go.

I'm going to kind of hi-jack this thread... this is probably going to sound stupid.

What kind of check cord do people use?

We have one that's a lunge line (long, cotton-web leash).

We just bought one from the sportsman show. It's a stiff, heavy rope with a big knot at the clip end. It's supposed to be specifically for recall training.

The trainer (Dan Mar) who sold them said to clip it on the collar under the dog's chin. Call the dog. If he doesn't come, give the cord a quick whack on the ground, and the knot will come up and smack the dog's chin.
It sounded good in theory. Problem is, it doesn't really work that way! Unless you have a straight line to the dog --he is looking directly at you or you're at a 90 degree angle, you can't smack him with the knot.
If he's turned away from you, it's useless. Maybe I'm just doing it wrong? :p

I did that years ago when my boxer was in her puppy obedience class. I got the webbing from the fabric store and clip at the hardware store.

I use the Permatack check cord. It is easier on your hands and doesn't tangle in the brush.  You can get directly from PermaTack or from Perfection Kennels.

Here is a picture:

Link to PermaTack: www.permatack.com/

This is like the one we bought.  I'm not real impressed.

Bxr -  Check cords like that will give you rope burn, especially when wet.  I noticed with the permatack that even when they wrap the legs, no rope burn.  They are a bit slippery when wet, but they don't burn your hands then either, and if you put a knot in the end like in the picture it helps allot.  They are also very light weight and don't tangle when stored.

I ran into the same problem.   I ended up keeping the dogs apart in the field for a bit and working them solo.  I then only let them run together for limited time at first....5 minutes, then one got put on the CC, then later 10, then 15, etc.  Took time and effort as i was out and about double duty but in the end it worked.

I also make my own CC's.  Just use some rope and a clasp from the hardware store...$5 total and works great and has lasted years.