JustIn

Current scoring systems are expensive, wired, and generally do not provide meaningful historical performance data. A wired scoring box costs $1,500 to $3,000 a strip and tethers both fencers to the floor. None of them record anything: a fencer finishes a season with no data about how they actually fenced.

JustIn is a wireless scoring and performance-measurement system for competitive fencing: hardware, firmware, mobile app, backend, and product design, built end to end as the flagship product of my company, Nytsu.

Fencing scoring hasn't meaningfully changed in decades: a wired box scores a bout and nothing else. JustIn keeps the accuracy fencers already trust and adds what's missing: no wires, and a record of how a fencer actually fenced.

Each fencer wears a microcontroller unit that talks Bluetooth Low Energy directly to a phone: no router, no strip wiring, no external infrastructure. The phone resolves scoring in real time and syncs bout data to the backend, where it becomes the historical record wired boxes never kept.

Épée touches are resolved with VirtualGround, a proprietary approach built to answer wireless épée scoring's core question: who touched first, without a wired, grounded strip to arbitrate it.

In August 2026, I conducted a two-hour live field test with fencing instructors and club members, running the entire class using JustIn's scoring system. The system operated successfully throughout the session, while the test surfaced concrete improvements for the next iteration.

Tested: whether JustIn's scoring (hit detection, touch resolution, and the app itself) could run a real class end to end, in place of the club's usual wired boxes.

Setup: an iPad running the JustIn app at my own fencing club. Instructors and club members fenced full bouts on it for the entire two-hour class. Not an app-store release: a controlled, in-person test on a working prototype.

Second field test, an analytics layer, further hardware refinement, FCC / CE certification, and paid club pilots.