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How to Climb

How to Climb: Expert Advice for Mastering Finger Cracks

From thumb-down jams to pinkie-down jams to donut jams, from finger bars to ring locks to tips cracks, there's lots of technique to be learned in just finger-sized cracks (to say nothing of all the other sizes!). Don't worry---Pete Whittaker's got you covered. He breaks it all down as simply as possible.

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Pete Whittaker's new book on crack climbing technique.
Crack Climbing: The Definitive Guide, by Pete Whittaker. 

Finger cracks are one of the most fickle sizes, as a small variation in crack or finger size can make a big difference in difficulty. Just one millimeter larger or smaller can be the difference between a move feeling easy or impossible.

Imagine a thin crack. Two people walk up to the route. One is a ballerina and one is a lumberjack. The ballerina has hands as thin as paper and fingers the width of matchsticks. The lumberjack has hands the girth of a tree trunk and sausage-like fingers. The ballerina climbs and dances up the rock, fingers locking and jamming with ease, whereas the lumberjack can’t fit a single sausage inside the crack and topples like a felled tree. Now, if we were to widen the crack by a few millimeters and again take our two climbers, we would find that our ballerina’s fingers would rattle inside the crack and she would have to use more difficult techniques to make them stick, whereas our lumberjack’s fingers would lock and jam easily. With finger-width cracks, very small changes can make a big difference.

The thought of sticking your body’s smallest digits into a crack, twisting them in ways they haven’t evolved to twist, and then pulling your body weight up on them, obviously makes people queasy and dislike this type of climbing. Fair enough! However, with the correct techniques, finger cracks can be climbed with relative ease.

Locker Finger Cracks

The dreamy finger jam: your fingers should sink, seat, and twist into the jam like a key in a lock. They will be buried inside the crack up to the base of your fingers and the jam will feel good.

Thumb-down jam: index finger

powerful jam, active twisting jam

As this is an active movement jam it can be used to great effect on complete splitters where there are few constrictions to passively jam between. (Remember when inserting a body part into a crack to always look for constrictions to jam passively first.)

1. Orient your hand into the thumb-down position (index finger and thumb towards the ground, pinkie finger towards the sky), pointing your elbow out to the side away from the center of your body. The back of your hand should be facing towards you, as if you were saluting someone.

2. Bend your hand, at the wrist, away from you so the tips of your fingers are now pointing towards the crack. Because you are bending from the wrist and not the knuckles your fingers should be relaxed and able to move freely. They are also in their thinnest orientation.

3. Insert your fingers into the crack up to their base, with your thumb on the outside of the crack.

4. Flatten your palm and forearm against the rock face; this creates a small amount of expansion in the finger pulp of skin at the base of your fingers.

Figure 2. Thumb-down jam: index finger. Illustration by Alex Poyzer.

5. Imagine there is a metal rod running up your forearm and through your wrist (so that you cannot bend or flex the wrist). Keeping this rigidity through the wrist and forearm, rotate your elbow and forearm down and in line with the crack. It is important to keep your forearm and palm close to the rock. If they move away from the rock, you will find yourself pulling out on the jam and not down. An outwards pull will negatively affect the quality of the jam, most likely forcing you into the dreaded elevator-door-opening technique (gastoning/backhanding the edge of the crack).

6. As you rotate with your elbow, your fingers will start to twist inside the crack (clockwise, if jamming with your right hand, anticlockwise if jamming with your left):

— your index finger will bite into the rock

— your middle finger will also bite (but slightly less so)

— your ring finger will gain some friction; however, it is common and correct for it to start rotating out of the crack and to leave it stacked on your front two fingers

— your little finger will come out the crack and should be placed against the crack wall

7. Your hand and forearm will now be parallel with the crack and you are ready to use the jam to move up on the route. When you start to pull up be careful not to move your palm and forearm away from the rock. Pull down on the jam, not out (figure 2).

Thumb-down jam: middle finger

powerful jam, active twisting jam

The same thumb-down jam can be performed but with your index finger out of the crack and your middle finger as the bottom finger in the jam. This can be useful if:

— the crack is ever so slightly too thin to fit your index finger in comfortably (it’s not uncommon for the index finger to be slightly fatter than the middle finger)you have done multiple jams using your index finger and this is becoming increasingly painful

Pinkie-down jam: little finger

powerful jam, active twisting jam

Although this jam has active movements to it, it works much better if you look for constrictions and aim to place it passively. And while there is some twisting involved in this jam, there is not as much as in thumb-down jams, which means that if you don’t find constrictions the jam can be marginal, feel like it is slipping, and be very strenuous to make work. However, if you can find the right spot, it can feel more restful than thumb-down jams—and can often be better than holding a massive jug.

1. Orient your hand into the pinkie-down position (pinkie finger towards the ground, index finger and thumb towards the sky), with the tips of your fingers pointing straight at the crack. Keep your hand relaxed. Your arm will be in line with the crack with your elbow pointing downwards—it is important to remember this and keep your arm in this position.

2. Insert your fingers into the crack, up to their base if possible. Look for constrictions that narrow down to become thinner than your pinkie finger, so that your finger can passively jam. Slide your fingers down into the constriction until your pinkie finger bites.

Figure 3. Pinke-down jam: little finger. Illustration by Alex Poyzer.

3. Whether you keep your index finger inside or outside of the crack will depend on how deep your fingers are inside the crack. As a basic rule, if three or more fingers have been inserted all the way to the base of the fingers, then keep the index finger inside. Also, if the jam is placed passively, this will reduce the need to rotate the wrist (see next step), meaning you can keep the index finger inside. If the jam isn’t placed passively, you will need to rotate more at the wrist and so the index finger will naturally start to twist out of the crack. If only one or two fingers go all the way to the knuckles, then keep the index outside. However, this is a guide: using feel to decide is often the best way.

4. This next part involves a very subtle twisting motion to make the jam work effectively. Being delicate is the key to success with this jam. Imagine placing a key into a “tricky to open” lock: using force and twisting vigorously will not work; you should gently and lightly feel for the best spot until it clicks into place. It is the same with this jam: don’t use brute force and over-twist; wait for it to click into place.

— Flatten your palm against the rock (keeping your thumb outside the crack) and then rotate it downwards. It is important with this jam to rotate from the wrist and not the arm. Your forearm should already be in line with the crack so there is no need to move it.

— Rotating from the wrist will twist the fingers into the crack, making them stick. If jamming with your right hand your fingers should start to twist anticlockwise, and vice versa (figure 3).

Pinkie-down jam: ring finger

powerful jam, active twisting jam

You can also execute pinkie-down jams with your ring finger as the bottom finger (figure 4). The same technique is used as with pinkie-down finger jams, the only difference is that your ring finger is the one biting into the constriction. Your little finger can either stay inside the crack (where it will be of limited use as it is too narrow to passively wedge) or move outside. Keeping it outside the crack will help to emphasize the twisting action on your ring finger. This technique is useful if:

— the crack is too wide for your little finger to jam, meaning it keeps sliding through the crack

— you have done multiple jams using your pinkie finger and this is becoming increasingly painful

Figure 4. Pinkie-down jam: ring finger. Illustration by Alex Poyzer.

Other Finger Cracks Included in Crack Climbing: The Definitive Guide

Baggy Finger Cracks

A difficult size of jam, in between the security of good finger locks and ring locks. A large amount of twisting force is used with these jams to get enough rotation in the fingers to enable them to make solid contact with the crack wall. They are a bad size and, I won’t lie to you, can cause some discomfort on the joints and skin from the amount of twisting.

Tips Finger Cracks

This jam sits either before, on, or only just past the first finger joint. As you have minimal skin in contact with the rock, tips jams are the most marginal of the finger jam techniques. They can feel awful in the wrong circumstances, however there are subtle tricks which can make even the most impossible moves doable. File those cuticles down and get those chisel tips out as things are about to get thin and every micrometer makes a big difference. The same basic hand positions can be used with this jam as with traditional finger jams: either thumb down or pinkie down.

Ring Locks

The ring lock is a difficult jam and requires practice to perfect it. This is because it entails using two different jams (an expansion jam and a twisting jam) in combination to form the final solid jamming position. The crack will be too wide to get a solid finger lock; even twisting your fingers hard won’t prevent them from slipping through the crack. However, the crack is still too thin to be able to start getting parts of your hand in. You need to start thinking laterally now: fingers and thumb need to work in harmony to make the jam stick.

Finger Bars

The finger bar is another technique for the ring lock size of crack (bigger than baggy finger, but too small to get the back of your hand in). Although this jam can’t be pulled on as powerfully as a ring lock, it is a useful tool for occasions when it is impossible to place a ring lock due to the nature of the crack: for example, if there are other rock features—a side wall or a flare—preventing you from doing so. Finger barring can be a painful technique when you do try to pull on one powerfully as it’s the type of jam that wants to bend your fingers in the wrong direction. Imagine placing your palm on the road and resting the tips of your fingers against the angle of the curb, then getting someone to cycle over the backs of your fingers. Ouch! That may be a bit extreme, but the point is they can be slightly painful even when performed correctly. However, with a small amount of pain tolerance and practice, finger bars can come in useful when ring locks can’t be placed.

Donut Jams

Sometimes cracks can be shallow, so they have no depth into which you can sink your fingers. (This is sometimes referred to as a box crack). Or there can be lots of little constrictions on the edge of and inside the crack; these can lend themselves to a unique technique. This technique is the donut jam, which has nothing to do with jam donuts. It’s a reference to the shape your fingers make when performing the jam—a round shape, like a donut. It was made famous by Didier Berthod in the film First Ascent. Didier is seen attempting the first ascent of Cobra Crack in Squamish with a sequence that involves him inserting his middle finger upwards into an undercut mono in the crack in the forty-five-degree wall above him. The donut jam can actually be performed with one, two, or three fingers. (When four fingers are involved it is closer to fist jamming.) Whether you use one, two, or three fingers, the principles are the same.

Pin Scars

Pin scars are artificial features in the rock, a result of aid climbers hammering pegs (pins) into seams and micro-thin cracks. Over the course of years, pegs that are hammered into the rock wear the rock down, expand the seams and cracks, and enable free climbers to fit their fat, callused fingers inside the openings. Pin scars are often more rounded, shallow, and not necessarily as secure as sinker finger locks. Pin-scar-style free climbing is particularly common in Yosemite. Yosemite’s granite is popular with both aid and free climbers, and lots of the free routes follow old aid lines.


Excerpted with permission from Crack Climbing: The Definitive Guide by Pete Whittaker (Mountaineers Books, 2020).


Available now!

Buy Now

Organized by width of crack (finger, hand and fist, offwidth, and chimney), Crack Climbing covers everything from basics like the hand jam through advanced techniques including the sidewinder and trout tickler.

To keep you motivated, Whittaker includes interviews with some of the world’s top climbers. Learn from the best, including not only Whittaker but also Beth Rodden, Lynn Hill, Alex Honnold, Barbara Zangerl, Peter Croft, Hazel Findlay, Nico Favresse, and more!

Also available at Mountaineers Books, Barnes & Noble and IndieBound.


Pete Whittaker is widely regarded as one of the finest crack climbers in the world, and is best known in the US as part of the Wide Boyz duo. He has made dozens of cutting-edge first ascents and hard repeats, including the third free ascent of Norway’s Recovery Drink (5.14c) and, with partner Tom Randall, the first ascents of Century Crack (5.14b) and Black Mamba (5.14b) in Canyonlands National Park. Follow him at @petewhittaker01 on Instagram, Facebook, and Twitter.