Your premise is not supported by evidence. One "researcher" made this claim, and provided no evidence to support it. There is nothing to support the notion that playing with prey reduces injuries to the predator.
>It keeps the cat's jaw (which is the part that delivers the killing bite, and which is the part that does the eating) away from the beak and teeth and claws, while the paws do batting and patting.
Paws are able to be bitten, scratched and infected just as easily as faces. The consequences of paw and leg injuries are in fact more dangerous than injuries to the face. It is hard to hunt when you can't run. There is no benefit to prolonging the exposure to danger by keeping the prey alive.
>It increases the chance of getting a kill, which is what gives the cat food after the hunt
A quick bite to the neck is the best chance of killing. Letting the prey struggle and escape to be re-caught is lowering the chances of getting food, not raising it. You are claiming the opposite of reality.
>That does not explain why feral cats, cats that need to hunt to survive, play with prey.
Yes it does. They only do so when they are teaching young to hunt. They do not play with their prey when they are engaged in the process of "acquire food to prevent death".
>Hunting a laser pointer is chasing prey, it is not playing with prey.
It is engaging in instinctive hunting behaviour for no benefit. Just like catching a mouse, playing with it, then wandering off.
All cats play with prey. Thus, it is evolved behaviour. It has some benefit, otherwise cats would just use the killing bite straight away.
> Paws are able to be bitten [...] there is no benefit to prolonging the exposure to danger by keeping the prey alive.
Cats have 4 paws. It's possible for a 3 legged cat to survive. Hard, but possible. The cat prolongs the exposure to danger of redundant limbs in order to protect the jaw.
> A quick bite to the neck is the best chance of killing. Letting the prey struggle and escape to be re-caught is lowering the chances of getting food, not raising it. You are claiming the opposite of reality.
A bite to the neck is the method of killing. Small animals are quick, thus the cat plays with the prey to weaken the animal so that when the cat applies the killing bite the small animal is less likely to escape.
> They only do so when they are teaching young to hunt. They do not play with their prey when they are engaged in the process of "acquire food to prevent death".
This is incorrect.
EDIT: You are incorrect about only one research suggesting that play with prey is a defensive part of hunting behaviour.
Trivial www searching find many different researchers suggesting this.
> In this article, we show that feline predation involves a continuous gradient of activation between defense and attack and that predatory "play" results from an interaction of the two. [...] In such shifts, no sharp demarcation between play and predation was evident. [...] These results suggest that play with prey is a misnomer for predatory behavior that fails to escalate along the gradient between defense and attack. Movement notation analysis revealed that playful movements are adaptive in that they protect the cat from injury.
Really? Did you have some evidence to support that claim? I can't find anything to support that notion at all. In fact, all I found indicates that wild big cats only play with prey in captivity, and when teaching their young to hunt. Wild cats hunting do exactly what you claim they don't do: they go straight for the kill.
>Cats have 4 paws. It's possible for a 3 legged cat to survive. Hard, but possible.
That does not address the issue at all. A cat with 4 healthy legs and an infected cheek is in a far better position to survive than one with a healthy cheek and an infected foot. There is no benefit to risking limbs over face, especially not risking limbs repeatedly for extended periods of time. And this all makes the completely unfounded assumption that "playing with prey" doesn't involve putting the face in danger, which is nonsense. Watch a cat play with a mouse, it will grab it with its mouth repeatedly during the process.
>This is incorrect.
Stating that doesn't make it so.