What do you think, of when you think of McDonald's? McDonald's hopes you'll start thinking chicken. 

No, they don't want you to forget about the Big Mac, exactly. But they do hope you'll soon think of McDonald's as your go-to place for chicken, before you think of Chick-fil-A, KFC, and its other chicken rivals.

That's their somewhat secret plan anyway. It comes complete with a codename ("Better Chicken"), and it was outlined in documents McDonald's shared with company franchises recently. 

The goal: make McDonald's into a "credible chicken player." (Doesn't that sound appetizing?)

Corporatespeak aside, I was wondering if something like this might be coming. 

A McDonald's in the U.K. caused a stir this week after it shared photos of a "Chicken Big Mac" on social media. (It turns out that the Chicken Big Mac does exist, but only in Australia--where it costs a little bit more than the beef Big Mac, by the way.)

Plus McDonald's has been pushing a "Seriously Chicken" menu across its locations in Canada, where the slogan is, "It's like Angus Beef if Angus Beef were Chicken."

But that tagline sort of sums up the issue for McDonald's.

We've all grown up knowing it (and lovin' it), as the home of "two all-beef patties..." But today, chicken is perceived as far more healthy than beef. 

"It's definitely a transformational era for McDonald's. Chicken is part of that," an analyst at Motley Fool, Jason Moser, told Bloomberg News, which reported the McDonald's strategy and said it had seen the strategy outlined in a franchisees' letter.

Among the things that are part of "Project Better Chicken"? (Or maybe that's "Operation Better Chicken"), according to Bloomberg:

McDonald's has already taken steps to elevate its poultry, which was long seen as a serviceable if uninspiring part of the menu. It's vowed to stop serving chicken with antibiotics and removed artificial preservatives from nuggets. The chain also rolled out Southern-style sandwiches and tenders, which are coated in a crispy buttermilk breading similar to Chick-fil-A.

So, why take on Chick-fil-A so directly?

Why not simply ignore its smaller rival--especially since that's basically what McDonald's does to Wendy's, when the smaller burger restaurant tries to bait the fast food leader?

There are at least 35 good reasons: the difference, in pounds, between the amount of chicken Americans eat every year--and how much beef they eat.

Red meat is going down, while chicken consumption is going up. And that goes straight to the bottom line.

Because while McDonald's is by far the most successful restaurant chain in terms of total revenue--300 percent higher than second-place Starbucks--that's largely because it has more restaurants (its own and franchised) than anyone else except Subway.

When you drill down a bit further, it's only fifth on the list in terms of average sales per store. Two of the three competitors right behind it, Zaxby's and El Pollo Loco, are chicken places.

Number one on the list, in terms of average store sales? You guessed it: Chick-fil-A, which makes almost twice as much per restaurant as McDonald's ($4.41 million vs. $2.55 million).