This guy has 2 videos on sharpening knives. Which is best.
https://www.youtube.com/watch?v=KBINMUdlJ14&list=RDCMUC2rzsm1Qi6N1X-wuOg_p0Ng&start_radio=1&rv=KBINMUdlJ14&t=715
is a $900 sharpener worth it? vs
https://www.youtube.com/watch?v=uEDyYJJ6f9M&list=RDCMUC2rzsm1Qi6N1X-wuOg_p0Ng&index=2