Hey everyone,
Having little experience working with wood, I encountered the same problem several times lately: When I split a log, the crack will eventually run off the logs center, to the side. I encountered it with maple and hazel, which split really easily , and hard to split birch (won't you split now, son of a birch!).
I use metal and wooden wedges, working my way from one side of the log to the other. The first wedge, the metal one, is driven into the logs central channel (or whatever it is called), the rest into the crack on the logs side. I start on the lower end (respective to the standing tree).
Any idea what I can do about this?