From what I read online, apparently a lot of people are cutting themselves wide open while merely trying to fix guacamole.
This is foolishness, folks.
I am so bad with knives that for years my husband begged me not to take a knife skills class at the community college. He was afraid he'd never see me again.
And yet, though I have eaten avocados several times a week for decades, I have never ever succumbed to the newly popular avocado hand (and by the way, the advice in that linked article about how to cut an avocado is nonsense).
Here's how to open an avocado without inflicting bodily harm.
1. Be pretty sure it's ripe, but not too ripe. If you don't know how to tell, see my post "How to get perfect avocados nearly every time."
2. Use a smallish knife--longer than a paring knife but not one of those big cleaver things. I use a cheap grocery-store knife with a 4½" blade.
3. Slice the avocado in half lengthwise, as in the picture (do not cut the pit). This is not the part of fixing an avocado that sends people to the emergency room.
4. Peel both halves, using your fingers (not the knife). It's much easier to work with a peeled avocado.
Now the plot thickens. How do you get that huge pit out? This is where people stab themselves when they only ever meant to affix the pit to the point of the knife. Resist the temptation: that's not how to do it.
5. Take the avocado half with the pit and slice it lengthwise again (do not cut the pit). You can slice it in half, or you can make a number of thinner slices. Once you have sliced it, the pit is easy to remove.
Bottom line: don't try to take the pit out of the avocado. Take the avocado off the pit.
You'll be fine.