Sounds good in theory, but I'm going to be charging at you with a knife, so even if I'm in excruciating pain my momentum would carry me straight towards you. I only need to get one good stick in.
I've never broken a major bone, nor been hit by a bat so I can't speak on experience from that perspective, but I've been in a lot of fights. In the heat of the moment with adrenaline and anger, you'd be surprised how much pain/what kind of hit you can absorb. At least that's how it's been for me at least.
I'll make you a bet. Let me stick you in the abdomen with a knife and we'll see how hard you can then swing a baseball bat.