Beta is a climbing term that designates information about how to ascend a climbing route (e.g. "grab hold of the flake on left while moving the right foot onto the edge on the right"). Traditionally sourced in climbing guidebooks, online databases and apps now provide very detailed climbing beta (e.g. videos of climbers completing the route). The term is attributed to Texan climber Jack Mileski.
When a climber completes a route on their very first attempt and without falling, it is called an onsight if they had no beta, or a flash if they had beta (a completion after several attempts it is called a redpoint). New grade milestones in onsighting and flashing routes are actively followed in the climbing media. The discovery of new beta has led to the re-grading of many notable and historic climbing routes.
Description
The complexity of beta can range from a small hint about a difficult section (i.e. referred to as "some" beta), to a step-by-step instruction of the entire climb (i.e. referred to as "the" beta). Sometimes there is more than way to climb a route and thus more than one beta; climbers can follow different route beta depending on their body shape (e.g. whether they have a long or short reach), and/or their preferred style and technique (e.g. may not have the power to overcome a roof, and thus take a different route). Multiple route options–and thus betas–are particularly common on long multi-pitch climbing and big wall climbing routes, for example on the famous Yosemite route Freerider and its optional "Huber boulder problem".
In rock climbing, beta can include background information about a route's grade of difficulty (e.g. what drove the grade), detailed aspects about the crux (e.g. "you need to use your left hand, not your right"), the climbing style needed (e.g. long reaches or tiny crimps), the best way to protect the route (e.g. "insert a number 4 SCLD before attempting the crack"), and specific information about hand or foot holds. For mountaineering and alpine climbing, beta may include information about the approach (e.g. crossing bergschrunds), the ability to find the correct route (e.g "avoid the crack system on the left"), the feasibility of exiting the route before completing it (e.g. key abseils to set up), and the situation regarding rock-fall and avalanche dangers.
Sometimes climbers capture the beta for the route into a graphical beta-map (which is similar to a topo). Advanced climbers on very difficult routes try to connect the beta of their route to their muscle memory, so they don't have to think about the next move.
Competition climbers are given a limited time to inspect the route as a group before the competition starts, but once the climbing begins, they must remain in the isolation zone away from the climbing wall, to prevent them learning more beta from watching fellow competitors attempting the route. During their time-limited pre-competition inspection, climbers try to work out the beta starting from the top of the route and working down, to avoid losing time.
The derived term spraying beta designates when a third party begins to impart unwanted beta without being asked for it (which can ruin an onsight attempt). The term breaking beta designates when a climber is able to bypass or skip a whole sequence of moves (e.g. using a dyno).
Access
The official climbing guidebooks were the first systematic forms of beta. The beta in these physical climbing guidebooks was limited to the basic details of the climbing route (e.g. length, grade, direction/topo etc.) so as to manage the size of the guidebook and avoid giving so much information that would spoil an onsight attempt. With the development of the internet, a significant quantity of more detailed beta began to accumulate (e.g. complete YouTube videos on how to climb a specific route). Both established climbing guidebook publishers (e.g. 'RockFax' in Europe), and the new dedicated online climbing databases (e.g. Mountain Project and 'theCrag.com') began to aggregate this detailed beta in online databases and apps, alongside the traditional guidebook-type information. Open-source beta databases such as 'OpenBeta' have also begun to aggregate user-generated climbing beta.
Origin
The original use of the term beta in climbing is attributed to the late Shawangunks and Texan climber Jack Mileski from the early 1980s. "Beta" was short for Betamax, an old videotape format largely replaced by the VHS format. Reputedly, Mileski would record climbers ascending routes on Betamax tape and then share these tapes with other climbers, resulting in the term becoming synonymous with getting information on how to climb a route.