DSLR Focus #2 - Focus Tracking & Accuracy!
The certainty of the intended subject point when your camera confirms focus - another key reason why DSLR still prefer to own over a mirrorless. As of 2020, Sony just about got there with their mirrorless AF, while folks like Olympus, Canon, Fujifilm and even Nikon Z (with the exception of their abandoned Nikon 1s) are still playing the catchup game in this department.
Nothing beats the joy of knowing for certain that all your focus point are diligently tracked accurately and quickly with each shot. Blurred or misfocused shots are what we want to minimise, having invested in any imaging tool.
And while we are at it, the 3D tracking capability of focused points in DSLR is still miles ahead of most mirrorless (save the Sony A9 series) camera today. Give it a go, and you would begin to agree too. A hybrid contrast/phase detect AF engine is the future.
So, if you already own a DSLR, keeping your focus mode to AF-C (3D/Group AF) will ensure that you are already optimized to benefit from the most reliable tracking engine for your moving subjects. Among some DSLRs, the total number of AF points can be toggled but I would simply leave it at the maximum available.
Never leave this on its default setting! Turn those knobs and optimize your cameras!