Accuracy, honestly
A referee, human or AI, earns trust by being right and by being accountable when it isn't. Here is exactly how good Verdict Fencing is today, how we measure it, and what it can't call yet.
Model accuracy current as of July 2026; dataset and labeling-pool figures as of August 2026. This page is updated as the numbers move. Measured results only, never projections.
Verdict Fencing is trained and evaluated on 25,224 quality-labeled saber touches from real competition video, each labeled by experienced fencers and referees with the winner and the action. "Quality" means the label was made at the top two confidence levels or was reviewed by the referee validation panel. Accuracy is always reported on held-out footage the model has never seen, grouped so that no bout appears in both training and evaluation.
31 fencers and referees label for us, 7 of them international referees, and they have produced 27,906 completed labels across 23,752 saber touches since February 2026. Every label records the winner, the action, and the labeler's own confidence in the call.
Calls that come back low-confidence are routed to a separate review panel: 5 validators, 4 of them international referees, have re-judged 3,258 of the hardest touches blind to the original call. Counting those reviews, 5,993 touches, about a quarter of the labeled set, have been judged independently by two or more people. The remainder carry a single confident label. Blanket double-coverage would be better and we do not have it; the honest description is targeted review of the touches most likely to be wrong.
Our labelers are anonymous by design. They work blind to each other, to the model's prediction, and to whose touch it is, so that seniority, reputation and deference stay out of the training data. In a sport where the referee's identity moves opinions, blind labeling is the only way to keep that influence out of the data. The trade is that we cannot offer you a named expert to trust, so we publish the pool in aggregate instead, straight from the annotation platform, and update it when it moves.
The foundation of every call is knowing where each fencer, and each blade, sits in every frame. Verdict Fencing's pose model tracks 16 keypoints per fencer, including the blade guard, midpoint, and tip, at 94.03% keypoint accuracy on held-out competition footage. Blade tips at full lunge speed are the hardest single thing to track in fencing video; this is where most of our engineering effort has gone.
One-light touches are unambiguous. The light decides, and Verdict Fencing just reads the box. The AI's job is the two-light touch, where right-of-way determines the winner. On those:
| Measurement | Accuracy | Notes |
|---|---|---|
| All two-light calls (held-out phone footage) | 77.1% | Every call, including ones the model is unsure about |
| High-confidence calls (top 25% by model confidence) | 95% | When Verdict Fencing is sure, it is almost always right |
Confidence matters as much as accuracy: when Verdict Fencing is not sure, it says so rather than guessing. In the app, low-confidence calls are flagged as such, the same way a good referee acknowledges a close call.
Every call comes with the action behind it, and naming the action is harder than picking the winner. These are action-recall figures, meaning how often the model names the action correctly. They are not winner accuracy. The two are different measurements and we do not mix them.
| Action | Named correctly | Status |
|---|---|---|
| Attack vs. counterattack | 83.8% | Strongest, and the most common two-light situation |
| Reprise | 64.1% | Solid |
| Attack in preparation | 53.5% | Middling |
| Parry-riposte | 47.6% | The weakest common call we make, and we publish it |
| Attack no | 29.0% | Under-called, and the least represented of the five in training |
The numbers above are measured on phone footage, because that is what the product runs on. The system has also been evaluated against broadcast video in partnership with a national federation; that work is not ours to publish, but it is the reason we are confident the approach is not overfitted to one kind of camera.
Better than it sounds, because there is often no single right answer to be 100% of. Ask two experienced people to judge the same two-light saber touch, blind, and they name the same winner about three times in four. That is the real ceiling, and almost nobody in this sport has measured it.
So we did. We ran a Referee Overlap study: 10 panelists (3 international referees and 7 experienced annotators) each called the same 100 held-out touches. No existing label, no other panelist's answer, no model output. 1,000 independent calls in total. Blindness is what makes the result mean anything: it separates disagreement about the touch from deference to the person calling it.
| Measurement | Result | What it means |
|---|---|---|
| Two panelists agree on the winner | 74.9% | Pick any two panelists and any touch: this is how often they match |
| Two panelists agree on the action | 56.6% | Naming the action is far harder than picking the winner |
| All 10 agree on the winner | 37 of 100 | Unanimity is the exception, not the rule |
| All 10 agree on the action | 12 of 100 | Same touch, twelve times out of a hundred, one story |
| Panel split three ways on the winner | 9 of 100 | Left, right and no-touch all called on the same exchange |
| Calls flagged as genuinely arguable | 2.5% | Panelists disagree confidently; they rarely think the call is close |
That last row is the one that changed how we think about this. Panelists were asked to flag any call a colleague could reasonably dispute, and they flagged 2.5% of them, while disagreeing with each other a quarter of the time. The disagreement is not people hedging on close calls. It is people confidently seeing different bouts.
The disagreement also tracks the rules rather than the footage. Panelists agreed 80.9% of the time on attack in preparation, and only 60.6% of the time on reprise. The actions where the FIE text leaves the most room are the actions people split on. That is an interpretation problem, not a video problem, and it is why we are not chasing 100%.
Three further lines of work, described here so you can hold us to them:
Study figures as of August 2026.
We're benchmarking end-to-end analysis time now and will publish measured numbers here. The same rule applies to speed as to accuracy: we only claim what we've measured.
Every number on this page is a snapshot, not a ceiling. The dataset grows weekly through our expert annotation team, and the two biggest known gains are in active development. When the numbers change, this page changes.
Early-access members get accuracy updates as they happen.
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