Climbing Grades Can Be Erratic. Is Darth Grader the Answer to More Consistent Grading?

At any crag, climbing gym, or campsite, climbers are often overheard dissecting routes into smaller segments: “It’s got a V5 boulder problem crux, a long section of 5.12b, and a bad rest right before the hard sequence.” Our various grading systems attempt to make sense of the path up a certain section of rock. But grading is inherently subjective and varies based on personal experience, climber type, local standards, and conditions.

How Climbing Grading Typically Works

The Yosemite Decimal System (YDS) and the French grading system are the two most widely used methods for rating the difficulty of rock climbs, helping climbers select appropriate routes. The YDS, primarily used in North America, employs a decimal system (e.g., 5.12a) to provide detailed grading, whereas The French grading system, common in Europe, uses a numerical and alphabetical scale (e.g., 7a+). Typically, grading is determined by the first ascensionist and experienced climbers through consensus, considering factors like technical difficulty, steepness, and overall effort required.

The subjectivity of grades can be frustrating for climbers at all levels. A move that feels impossible when you’re pumped and fatigued can seem laughably easy after a rest. Grades attempt to account for factors beyond technical difficulty. Endurance, mental strength, conditions, and beta (the sequence of moves) all play a role. And traditional grading systems rely heavily on perception, leading to inconsistencies across regions and styles.

Darth Grader: A Systematic Approach to Grading

Enter Darth Grader, a platform that claims to propose a more systematic and mathematical way of assigning climbing grades. Darth Grader was born from a passion for climbing and a curiosity about the way routes are graded.

Created in 2022 in Grenoble, France by a group of climbers and routesetters with skills in mathematics and programming, the tool began as a simple console application designed to test a hypothesis: Could the breakdown of a route’s sections and rests accurately predict its overall grade? The early results were surprisingly precise, and the enthusiastic feedback from the founders’ friends inspired them to develop a web version. Today, Darth Grader aims to enrich the climbing experience by offering a structured way to compare personal impressions with established grades, encouraging dialogue and fostering consensus within the climbing community.

Could this tool bring some objectivity to the otherwise subjective exercise of grading?

Watch a walk-through of how the Darth Grader tool works

How Darth Grader Works

Darth Grader is a free, interactive website that breaks climbing routes into smaller sections—such as cruxes, endurance sequences, and rests—and assigns points to each. Hard cruxes and poor rests increase difficulty, while good rests reduce it. The system then calculates a total grade based on these inputs, minimizing the biases found in traditional grading methods. Each section is assigned a grade, either a V-grade for a crux or a YDS grade (e.g., 5.12a) for a longer section, reflecting how that segment would feel when you’re fresh, right off the ground.

The tool works by linking each section through a step-by-step process using an iterative algorithm and a mathematical parametric formula, which accounts for factors like difficulty and rest quality. Instead of relying on artificial intelligence or large datasets, Darth Grader is calibrated using a trusted database of benchmark routes—climbs with unanimous grade agreement and repeated ascents by many climbers. This ensures its calculations reflect real-world climbing experiences.

Additionally, the tool bridges different grading systems—such as the French scale, the Yosemite Decimal System (YDS), the V-scale, and the Fontainebleau—using correspondence tables. These help ensure Darth Grader remains accurate and accessible, regardless of climbing style or grade, from moderate beginner routes to the most challenging test pieces.

One of Darth Grader’s key innovations is factoring in the quality of rests. Climbers can categorize rests as good, medium, bad, or nonexistent. A good rest allows near-full recovery, while a bad rest offers little relief. The quality of a rest significantly influences how climbers perceive the difficulty of the next section. However, subjectivity still plays a role—a “good rest” for one climber might feel useless to another, depending on fitness level and experience. That boulder problem at the top of the route might feel like a V7, but actually only be V3 and you’re just pumped out of your mind.

The tool can also be used to calculate bouldering grades. Boulders can be broken down by either a single move, longer sections, or both. However, there are no rest sections factored in. Furthermore, the website has a multi-pitch function that can determine the overall “effort” required to send an entire multi-pitch route. For example, if a multi-pitch has three pitches of 5.12a in a row, it would calculate the entire route as having the overall grade of 5.12d, since that’s the “effort” required to send the entire thing.

How to Use Darth Grader for Your Climbing

While Darth Grader isn’t a replacement for traditional grades, it’s a valuable tool for breaking down routes and understanding their difficulty. Imagine a climb you’ve projected for weeks. You can recall every move, rest, and crux. Using Darth Grader, you could work backward from the consensus grade to break it into sections and better understand how the overall difficulty is calculated.

Take Primate, a popular 5.13b in the Flatirons of Boulder, Colorado. It might be described as: 5.12a > medium rest > V5 > good rest > V5 > good rest > 5.10d. Darth Grader calculates this as a soft 5.13b, provided there’s agreement on the section grades and rest quality. But if the first crux feels more like a V6, Darth Grader will still land on 5.13b, though a harder version of the grade.

This level of detail helps climbers refine their understanding of a route’s difficulty and maybe even better train for a project. If you know the route has several V5 cruxes in a row with good rests between each, you can hit the bouldering gym and do some on-the-minute bouldering, instead of doing laps on easy routes to work your endurance.

The tool’s emphasis on section breakdowns and rest quality provides insight into why certain routes feel easier or harder for different climbers. For example, a climber with strong endurance might breeze through long sequences, but struggle on a single hard move. Darth Grader can clarify how these sections interact to create the overall grade.

While Darth Grader is designed to be user-friendly, it does require climbers to have a basic understanding of grading systems. Users need to evaluate the difficulty of individual sections and the quality of rests along a route, which involves some familiarity with climbing grades and the ability to make subjective assessments.

It’s also important to note that the tool has its limitations. Darth Grader can struggle with routes that are highly inconsistent, such as those with one extremely difficult move surrounded by easier climbing, or with long boulder problems that blur the line between a boulder and a route.

Despite these challenges, the tool remains a valuable resource for analyzing most routes, helping climbers better understand and discuss grades while acknowledging the inherent subjectivity in climbing.

What Route Developers Think About Darth Grader

Dean Ronzoni, who recently completed the first ascent of Later Creators (5.13c) in the Flatirons, has been using Darth Grader for the past two years as a reference to validate his initial impressions of a route.

“I approach FA (first ascent) grading by combining personal experience with comparisons to nearby climbs,” Ronzoni explains. “Darth Grader acts as a sanity check, especially for harder routes (13a and above), because it breaks climbs into boulder problems instead of assigning a single grade. It’s accurate enough to build trust, though consensus grades evolve as more climbers find new beta.”

Prolific first ascensionist Matt Samet has seen grading evolve since he drilled his first bolts in the late 1980s.  Samet dismisses the idea that Darth Grader makes grading feel too sterile. “It makes grading fun, gamifying the process and sparking cool discussions about route breakdowns,” he says. “I enjoy experimenting with different section grades and seeing how that impacts the overall difficulty.”

Samet also appreciates Darth Grader’s objectivity, though he takes it with a grain of salt. Many of his routes have been upgraded or downgraded over the years. “I use it to determine a grade based on identified cruxes and sections,” he says. “Then, because it’s the Front Range, I subtract at least one letter grade. That’s some math for you!”

The Future of Grading

Darth Grader isn’t the ultimate answer to climbing’s grading conundrum, but it’s a step toward a more universal language. As the climbing community experiments with this tool, it could revolutionize how climbers discuss and compare routes. The structured approach encourages deeper reflection on why certain climbs feel easier or harder, and to observe how accurate your route descriptions are. Do you tend to exaggerate the difficulties—downplaying challenges and sandbagging other climbers—or do you hit the mark just right?

However, even the most precise algorithms can’t capture the exhilaration of clipping chains after a hard-fought battle on the wall. Darth Grader offers a new lens to explore this complexity, but it’s up to each climber to decide how—or if—they want to use it.