I was boring holes for stool-legs when this huge chunk of hard maple tore out. This was supposed to the be the top surface of the stool, so it's pretty frustrating. The chip was mangled, so I can't glue it back in place.
It's a sharp 1-inch auger bit in a bit brace; what was I supposed to do differently here to prevent ruining the surface?
Sometimes you just can't prevent all surface tearing when drilling directly into wood. Sharp bits do help — and by sharp I mean sharp, sharp enough you want to handle the bit with care because you fear cutting yourself.
Also specific designs of bits drill cleaner holes (more on this below) but this chip is particularly severe, being both large and deep, and this could indicate that the wood was partly to blame and could have chipped out even if one or two steps had been taken to minimise/prevent this.
This is why I think the last tip below is the tip to try to take advantage of when the workflow means you are having to drill into a near-finished surface.
It's a sharp 1-inch auger bit in a bit brace; what was I supposed to do differently here to prevent ruining the surface?
Tips to help prevent tearing when drilling holes go back a long way and the earliest how-to woodworking books usually include one or two. They can sure help, but I've tried every one I've read once or twice (in various woods, with various bits) and none is 100% effective.
With auger bits and drilling angled holes specifically one of those tips was to drill perpendicular first, so the spur or spurs can (as much as possible) cleanly sever the surface fibres, before then tipping the drill to the desired angle and complete drilling the hole. This can work well, sometimes1, but even when it does it leaves a hole that is less than perfect to say the least.
Modern tips include:
Apply tape to the surface and drill through it.
Pick the drill bit specifically for its ability to create good entry and/or exit holes. Forstner bits2 are most commonly mentioned in this context.
Tape
This does not work as well as claimed; and what's more removing the tape can subsequently lift flakes (just as it does when used to help during sawing) so it might even make the problem worse sometimes.
Picking a suitable bit
This is a strategy that definitely works, when you can use it. But there are plenty of situations when you can't — e.g. no bit of the right type is on hand in the size needed, the right bit type can't be used in the location needed.
But the best tip of all I think is:
Don't drill directly into a final surface
There are two ways of implementing this, plan to plane or sand the surface after the holes are drilled, or support the surface fibres of the wood with a secondary block. Both work, but the best is the second because it always works, if you can arrange it.
In the first version you haven't finished dimensioning the piece before drilling, and finish-planing or the last sanding operations will get you down to dimension and take care of the chipping while you're doing so. I like doing this myself and use it frequently, but it's hard to arrange to plane away exactly the right amount of wood to get below any chipping that might occur!3.
So, this leaves drilling through another piece of wood. This piece MUST be firmly against the surface of the workpiece or it doesn't help, so you either clamp it firmly to the workpiece or have it held in place by hot-melt glue or some other adhesive strategy. If this secondary piece is pre-drilled it can additionally act as a drilling guide to ensure the correct angle (even a plain 90°) is followed, useful when drilling angled holes for splayed legs or perpendicular holes in the middle of a large flat surface, such as bench dog holes.
1 Although occasionally as soon as you tip the drill and go deeper a chip is lifted :-(
2 And modern developments of it such as toothed or wavey-rim bits.
3 Meaning that sometimes you either have to leave some chipout, or fill it, neither of which is entirely satisfactory.
The picture appears to show that the screw in the auger bit grabs the hard wood and pulls the bit down very strongly. You can see that the bit grabbed one side very deeply while not even catching the other side. Going so deep allowed the bit to lift the grain outside of the diameter of the bit before it even has severed the grain in the affected area. A forstner bit does not have a screw at center and cannot grab the wood and pull down. 
It uses many smaller teeth at the perimeter to cut the outer edge of the hole and relies on the pressure of on the drill in order to progress.
