Here is the way I do
start a thin wedge at crack in growth center ,then a wedge from the side of log that will knock the first wedge out as it goes in, then keep driving wedges in from that side to move down along the log , start each new wedge at the point farthest from the last one that you can still see through the log no further a way or you will be starting a new split !
Read this twice then ask Questions
"keep it simple keep it fun"
Guy