>>793679>the 80's>you never baton anything thicker than three fingerThat was a good rule of thumb in the 80's, however it should be updated. There are much stronger knives today, maybe it's four fingers now, it depends on the knife. The problem is youtubers expect a "tough" knife to split any log, which of course is not possible.
It's not just the diameter of the wood being splitted. If you try to split a log, don't use brute force. If the blade is not moving as is should when you hit it, stop batoning at once and try another angle.
Imagine the worst test bench imaginable. You put the knife between three angled steel beams, two on the left and one on the right, middle of the blade. Then you hit the blade with a hammer adding more force with each hit.
The blade will not break until you hit it so hard that the blade can no longer absorb the energy by bending.
As long as you don't hit too hard, it's impossible to break a good knife, even if it was a huge log. Unfortunately, if the wood won't split, that's unacceptable for most youtubers. They see it as a failure and keep hitting until the unevitable happens.