Dang it, lost my post?
Check the SOP of the breeds - they often have very good points, and pictures of things to look for.
You need to pick them up, and feel them over, feathers cover a lot of sins. Examine their feet and legs, breastbone, and head carefully.
The feet you want to be symmetrical, look for crooked toes, or twisted nails - these can be hard on balance and hen's back as they breed.
Look carefully at the head and beak, you want symmetrical alignment, not even a hint of a crooked beak.
Feel the breastbone, and thighs. At first you might not feel like you know what you are feeling for, but by handling the 4 of them, you will get some experience and start to notice differences.
Weigh your birds, I am assuming they are the same age, and had the same food, heavier birds are better doing birds.
You are not judging for which to keep at this stage, but rather who to let go first. I would recommend removing 1 and waiting 2-3 weeks, it will change their dynamics. Often times, one will stand out of the three, but if not, remove one more, wait and then make your final decision.
When it gets down to the end, I had a successful chicken lady tell me, she would remove one from the flock but not cull, seeing how the lone rooster interacted with the ladies, if she was happy with that, she did cull the removed bird, but if she wasn't, she flipped them.
Mrs K
If he scrambles to get it and runs away with it to enjoy for himself every time, then tidbitting isn't in his nature.
