it ain't about experience
Not required for an experienced operator. Problem is though, an experienced operator isn't the one you have to worry about reading "safety devices are useless don't use them" and lopping a finger off.
Saws come with splitters/riving knives because they work. They work because of the physics.
Keeping the board against the back of the fence prevents kickback. Put on your body armor and let the board come off of the fence at the rear and see what happens. Experience has nothing to do with the physics AND experienced woodworkers often take shortcuts because they have "experience" BTDT.
Keeping the kerf open is the other advantage. Put your body armor on a make a kerf part way down the board, then pinch the kerf together behind the blade and if you are lucky, and you have a saw with less than a 5 HP motor, you may be able to stall the motor in enough time to reach the OFF switch before it shoots back at you. It has nothing to do with experience and a whole lot to do with the wood movement in certain species or grain orientation .... the physics.
The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)