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Devlog

21 posts

2026

Stick Figures Beat Smudges

·5 min read
devlogcomputer-vision

The forehand-or-backhand call has been stuck for two weeks. The fix: draw a skeleton on every player and read the actual swing.

The Court That Fits Itself

·5 min read
devlogcomputer-vision

A human has clicked four corners for every match this project ever charted. A free pretrained network just took the job — and knew when to refuse it.

The Machine Grows Ears

·6 min read
devlogcomputer-vision

The ball tracker blinks at the worst moments. Broadcast microphones don't. The software learns to listen for the pock of strings on ball.

Nobody Sees the Ball Land

·7 min read
devlogcomputer-vision

The machine couldn't tell wide errors from deep ones. The fix: stop trying to watch the bounce and calculate it, like Hawk-Eye does.

The 33rd Charter

·7 min read
devlogcomputer-vision

Court Vision introduces itself to the real volunteers who chart tennis matches by hand, and asks whether its drafts actually save them time.

The Benchmark Grows Up

·10 min read
devlogcomputer-vision

A bigger test made the trust score honestly drop — then a check that could never fail got caught, and the score climbed back up.

The Draft Grades Itself

·8 min read
devlogcomputer-vision

A confidence flag tells a volunteer chart-corrector which draft points to trust — and this post checks whether the flag itself can be trusted.

Within One Token of a Human

·11 min read
devlogcomputer-vision

The project finally gets an honest report card: how many fixes would turn the machine's chart into a human's? Today's first answer: 2.2%.

The Score Bug Is the Point ID

·7 min read
devlogcomputer-vision

A TV scoreboard graphic nobody notices turns out to be the only reliable way to tell where one point ends and the next begins.

The $0 Specialist and the Load-Bearing Bug

·6 min read
devlogcomputer-vision

A free specialist replaces an expensive all-purpose tracker — and exposes that its rival's biggest flaw was secretly marking the end of every point.

T1: Right Hardware, Wrong Sign

·5 min read
devlogcomputer-vision

Graded against a real human chart for the first time, the system's biggest miss was a lefty problem, not a broken tool.

T1: A Test Set With Answers in the Back

·6 min read
devlogcomputer-vision

The software faces its first honest test against a match a human already scored, and the camera math needs fixing first.

M3: The Ball Gets a Vote

·8 min read
devlogcomputer-vision

When the software can't tell who hit the ball, it holds a vote instead of guessing — and the ball outvotes the serve call, on camera.

M3: The Toss Is the Bootstrap

·4 min read
devlogcomputer-vision

The serve toss lets the software find the ball itself, and it charts its first full point without a human drawing a single box.

M3: The Static Camera Isn't

·6 min read
devlogcomputer-vision

The 'still' broadcast camera actually drifts mid-point — and that breaks a free trick for spotting players in video.

M3: The Cutting Room

·7 min read
devlogcomputer-vision

Most of a tennis broadcast isn't the match — the software has to spot the one camera angle that actually shows it.

M3: Who Hit That?

·8 min read
devlogcomputer-vision

The software found the players by noticing who never moved, then called every forehand and backhand from where the ball crossed their body.

M2: The Court Doesn't Return Serve

·7 min read
devlogcomputer-vision

Teaching software to spot every hit and bounce in a rally, just from watching the ball's path bend.

M1: From Pixels to Meters

·7 min read
devlogcomputer-vision

How four painted corners taught the software to turn a TV picture of the court into a real, to-scale court diagram — for free.

M0: Can SAM 3 Hold Onto a Tennis Ball?

·7 min read
devlogcomputer-vision

An AI that finds objects by description can't tell one tennis ball from six on court — until you point at the one in play.

Teaching a Computer to Watch Tennis

Teaching a Computer to Watch Tennis

·5 min read
devlogcomputer-visiontennis-data

Can a computer watch a tennis broadcast and write down every shot, the way a courtside volunteer does by hand?