It would depend on what, if anything, the victim did it to initiate contact with the dog. It is reasonably expected that humans are going to approach dogs to have a friendly interaction.
It is normal for people to approach a dog to pet it, to play with it, or kneel down so that the dog can come closer. All of the normal activities that humans do to initiate contact with dogs are completely accepted under the law. If you reasonably initiate contact with a dog, and that dog bites you, the owner of the dog is liable.
But if a dog is behind the fence, and there is a giant “Beware of Dog” sign and you hop over the fence to interact with the dog, you likely have no case.
If you’ve been injured in a dog attack, regardless of the circumstances of the attack, it’s strongly advised that you speak with an experienced dog bite injury lawyer as soon as possible.