Bouldering grades: V scale, Font scale, and honest conversion ranges

What to look for

Bouldering grades: V scale, Font scale, and honest conversion ranges. Use a practical three-checkpoint method, compare repeatable attempts, and choose one next training action without treating one video as a verdict. Focus on the visible clue, the local convention or context, and the uncertainty you must keep. Those three checkpoints give you a repeatable review without pretending that one camera angle can explain everything.

Film a useful rep

Keep the whole movement and every relevant contact point in frame from a stable coaching angle.

Record two or three technically comparable attempts. Keep the camera fixed, avoid digital zoom, and include the setup before the movement begins. A stable frame makes changes in timing, position, and control easier to compare.

Review one phase at a time

Watch once at normal speed, then move frame by frame. Mark the start, the main transition, and the finished position. Compare the same phase across attempts. Write one direct observation, then choose one cue you can test in the next set.

Turn the review into training

Use a lighter or simpler variation when you cannot repeat the target position. Keep the task narrow for the next few attempts, then record again from the same angle.

Treat every conversion as a range

The V scale and Fontainebleau scale describe difficulty, but neither scale creates laboratory precision. Setters, rock type, hold texture, wall angle, height, style, and local convention all affect the grade. A converter should return a likely range, not one allegedly exact equivalent.

For example, a problem near V4 may overlap roughly with the Font 6B to 6C area depending on the chart and local setting. Use the converted value to find a starting problem, then recalibrate against the gym or crag in front of you.

What changed?	Why the same grade can feel different
Wall angle	Overhang increases the demand on grip and body tension
Hold type	Slopers, crimps, and compression reward different strengths
Reach	One sequence may change for a shorter or taller climber
Setting style	Coordination, power, balance, and endurance distribute difficulty differently

Log the original grade system with every attempt. Do not convert a converted number again.

Use a repeatable comparison protocol

Before the first attempt, define the question you want the recording to answer. Write down the difficulty, load or variation, planned repetitions, and main cue. Do not change the phone angle, height, or distance during the set. You are building a reference you can reuse in the next session instead of restarting the review from memory.

After each attempt, score the visible clue, the local convention or context, and the uncertainty you must keep separately. Write visible facts. “Both feet landed at the same width” is more useful than “the technique looked bad.” If the frame hides a phase, mark it as unobservable. Never fill a missing frame with a guess.

Checkpoint	What you compare	A useful decision
the visible clue	The same position and moment in two attempts	Keep or simplify the setup
the local convention or context	The order, rhythm, and path of the transition	Test one cue only
the uncertainty you must keep	Control and stability at the finish	Repeat, regress, or end the set

Choose the next action

Keep the variation when you reproduce the target checkpoint across several attempts. Reduce the difficulty when the position disappears as soon as you add speed, fatigue, or load. Progress only when you preserve the same checkpoint without changing the entire movement. This rule separates one lucky result from a skill you can repeat.

Do not correct three things at once. Start with the change that happens earliest in the movement because it can affect every phase that follows. Test it across two or three comparable attempts. If the recording shows no change, remove the cue and test a different explanation instead of adding more instructions.

Track three sessions

In session one, create a reference clip and choose one checkpoint. In session two, film the same variation under similar conditions and check whether the change remains visible. In session three, raise the difficulty slightly and see whether you keep the checkpoint. That short run of personal evidence tells you more than a highlight reel of your best repetitions.

Read the filming guide before you place the phone, then use the training tool to plan the next step. These pages help you keep the same review process across sessions.

Avoid common review errors

Do not compare two camera angles, a fresh repetition with a fatigued one, or a slow variation with an explosive attempt. Do not draw precise conclusions from a blurred or cropped clip. Compare one visible checkpoint under similar conditions.

Pre-session check

Clear enough space before you train. Put your phone on a stable support outside the movement area, use good lighting, and wear suitable training or protective equipment.

Repeat the process only when the comparison still answers a useful question. If the next clip looks different, check the setup, camera position, variation, load, and fatigue before you assume your technique changed. Keep the observation provisional until you reproduce it. This protects your log from confident conclusions built on incomparable attempts.

Use video as a comparison tool, not a verdict. Change one variable, record the next set from the same angle, and compare like with like.

Keep the review with your training log

Save the clip, the cue you chose, and the result of the next attempt together. That gives you a useful record instead of a camera roll full of disconnected videos.

Open Bouldering AI, record one comparable attempt, review one checkpoint, and save one cue for your next session.

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