How a tree actually falls

Last updated 10 September 2026

A falling tree is not steered by the cut you are making. It is steered by the wood you choose not to cut. Almost everything else follows from that one sentence.

Three cuts, and only one of them is the point

The face notch

A wedge cut into the side of the trunk facing the direction you want the tree to go. It does two things: it points the tree, and it gives the trunk somewhere to rotate into. Cut it too shallow and the tree cannot commit; cut it too deep and you have eaten the wood you needed for the next part. Its depth is conventionally a fraction of the trunk's diameter, not a fixed number of inches — a big tree needs a big notch.

The angle matters too. A wide open face lets the tree rotate all the way to the ground with the hinge still intact and still steering. A narrow conventional notch closes partway down, and the moment it closes the hinge snaps and the tree is on its own.

The hinge

The strip of uncut wood left between the notch and the back cut. This is the whole thing. It is what holds the trunk to the stump while it tips, and it is the only control anybody has over where a tree goes. Leave it even, and the tree follows the notch. Leave it thicker on one side and the tree pulls toward the thick side. Cut through it and there is no steering at all — the tree simply goes wherever its weight was already taking it.

A hinge is thin. It is a small percentage of the trunk's diameter, and the instinct to leave "plenty, to be safe" is exactly wrong: too much hinge will not break in a controlled way and starts tearing wood upward out of the stump.

The back cut

Cut in from the opposite side, toward the notch, stopping at the hinge. Its job is to remove the wood holding the tree up so that its own weight rotates it over the hinge. On a conventional notch it is placed slightly above the notch apex, so that the remaining step of wood — the stump shot — keeps the butt from sliding backward off the stump toward the person who just cut it.

Reading the tree, which happens before any of that

A tree has an opinion about where it wants to go before anybody touches it, and the cutting plan is mostly a negotiation with that opinion.

• Lean. Both kinds. Forward lean along your intended fall line is help; side lean across it is the one that ruins plans, because it works on the hinge the entire way down.
• The crown. Weight up high is leverage. A trunk that looks plumb with all its branches on one side is a leaning tree.
• The wood itself. Species differ enormously in how their fibre behaves under tension. Short-fibred woods let go early and abruptly; a hinge that would hold fine in fir can fail in aspen, which is why cutting every tree the same way eventually finds the one that does not cooperate.
• What is overhead. Dead limbs and hung-up branches come down when the trunk moves, and they come down on the person standing under them.
• The way out. An escape route cleared beforehand, angled back away from the fall line, walked before the cut rather than discovered during it.

The barber chair

The one worth knowing by name. A barber chair is when the trunk splits vertically instead of hinging over: the front half goes with the tree and the back half rears up off the stump, backward and upward, at roughly the height of the person cutting it.

It happens when the fibres are under too much tension for too long — classically a heavy forward-leaning tree cut slowly from the back, where the wood is being pulled apart faster than the saw is removing it. Leaving a shelf of uncut wood below the notch does the same thing: the trunk has to split through it, and split is exactly what it does.

It is not a freak event and it is not bad luck. It is the same moment balance as every other fall, resolving badly because the cut sequence let tension build where it should have been relieved. On a heavy leaner the answer is to relieve that tension before it can accumulate — which is what bore cutting is for, and which is exactly the sort of thing to learn from an instructor standing next to you rather than from a paragraph.

Why it is worth simulating

Every one of these is arithmetic: a mass, a centre of gravity, a moment arm, and a strip of wood with a known strength holding it. That is a solver, not an animation. And once it is a solver, the same tree and the same cuts give the same fall every time — which is the only condition under which technique is worth learning at all.

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