Most kickbacks don't "just happen". Knowledge is power. If you understand the things that can contribute to a kickback you will understand what you can due to reduce the risk of a kickback..
Let's start with the diagram below, the one with all the letters, numbers and colored arrows. The Red Arrows are the ones that cause most kickbacks. The Green Arrows are the things that can reduce the likely hood of a kickback.
The red arrows are the things that want to cause that spinning blade to throw the board back at your stomach or groin (Red Arrow A ), or up in the air and then back at your face (Red Arrow B ).
If the back of the kerf closes around the back of the blade (Red Arrow C & D) the teeth at the back of the blade (the Green Teeth) can contact the board, lifting it off the table and up into the saw teeth (the Red Teeth), which are spinning TOWARDS YOU
If Fence "a" is closer to the back of Blade "b" than it is at the front of the blade, the wood can be pushed into the the back of the blade (Red Arrow C ) where it comes in contact with the teeth which are travel UPWARD. These saw teeth (the Green Teeth) can lift your stock up off the table and up into the teeth which are spinning TOWARDS YOU (the Red Teeth). Just so you know, the tips of the saw teeth are traveling at about 120 to 150 miles per hour on a 10 inch diameter saw blade
If you're cross cutting a board using the miter/mitre gauge, you introduce another potential cause of kickback. If the saw blade is not parallel to the mitre slot you won't get a square end on the cut board. But if the back of the blade is closer to the mitre slot than the front of the blade, the back of the cut will be pushed into the teeth at the back of the blade (Red Arrow D). That can cause the rear teeth to lift the board off the table into the teeth at the top of the blade. Those teeth are spinning TOWARDS YOU.
If you're cross cutting a board and are using the fence to position the cut off length you are asking for trouble, especially on boards narrower than the length of the exposed blade above the saw table top.
We'll get to the Green Arrows and the things you can do to minimize kickback later, AFTER you get a feel for the things that can contribute to kickback.
So let's see some of the things that can contribute to kickback --->