Anyway, I think that my critics make sense. Actually the start of the relationship between Seol-a and No-Rae (the guy trying to strangle her and No-Rae to the rescue) was odd too. Why would you use a baseball bat on some random guy? Any normal person would probably have screamed at the top of their lungs. That's what I would have done if I had witnessed such scene.
Um, this might what you of done but using force on someone assaulting another person isn't something a "normal" won't do especially for acquaintance/friend/loved one. Granted I would of not aimed for the head because that can turn into a deadly blow very fast, but it's the way base all bat hits happen in all fiction. It's the one hit knockout.
For future reference, first hit should be on his side for cracked / broken ribs and air loss. Second hit should be to the kneecap or Tibia to shatter bones, it sorts of pretty much immobilize your target. Should be fairly easy since his body will naturally go to the side and expose his legs ( coping with the hit ). You then can go for the takedown and immobilize them while calling for assistance from cops/other people. If it's not enough because bad hits/not enough force, just hit the legs again.
Now you all know how to beat someone up in the particular position the guy was in if you happen to randomly walk in a situation like this with a bat.
P.S. This is totally doable if you passed bio in high school and know how the body moves.