In a large, glass, mixing bowl, add cider vinegar, lemon juice, lime juice, mustard, brown sugar, garlic, salt, and pepper. Mix well.
Using a wire whisk, whisk in olive oil.
Place chicken breasts in marinade, turn to coat, cover with plastic wrap, and place in the refrigerator to marinate a minimum of 8 hours, or overnight.
For the Chicken:
Preheat the outdoor grill to high heat.
Prepare grill by lightly oiling the grate.
On prepared grill, add chicken and cook for 6 - 8 minutes, flip and cook another 6 - 8 minutes on the other side, or cook until the chicken is no longer pink inside, and the juices run clear.
Discard the marinade.
***Note: The points and nutritional values per serving are calculated using all of the marinade since it isn't possible to calculate marinade by serving accurately. So, the nutrition and points will be less in reality. MyWW Points: 9 Blue Plan and 11 Green Plan9 WW Freestyle Points 11 Smart Points