Pitch charting without a scorekeeper

A pitch chart is a record of every pitch a pitcher throws in a game, in the order they were thrown. For each pitch it notes the type, the count it was thrown in, where it went and what happened. Added up, it gives the pitch count for each pitcher.

A scorebook records what happened to each batter. A pitch chart records what the pitcher did to get there.

• Pitch counts and workload, game by game.
• How often a pitcher gets ahead with the first pitch.
• Which pitch a pitcher goes to when behind in the count, and which one with two strikes.
• Where the misses go, and whether they change late in an outing.
• What a hitter saw and did in each at-bat.
• A plan for the next bullpen session that starts from the last game.

Someone in the dugout keeps it on a clipboard or a tablet: often a pitcher who is not throwing that day, a student manager or an assistant coach. They mark each pitch as it is thrown. If the staff wants velocity, a second person holds a radar gun and calls out the number.

It works when that person is free for the whole game. When they are sent to warm up, to coach a base or to find a helmet, the chart has a gap. A head coach cannot keep it and run the game at the same time.

You film the whole game from behind the plate and upload the file after it. Nobody charts during the game. Most games are ready in 10 to 20 minutes. What comes back:

• Every pitch in game order, each one timed to the video.
• Pitch type and AI-estimated velocity for each pitch.
• The count for each pitch, and how each at-bat ended.
• Pitch counts for each pitcher, with average and top estimated velocity.
• Filters by pitcher and by inning.
• Strike zones and pitch mix for the game.

Click a pitch in the log and the video jumps to it. You can flag a pitch and add a note for your review list, and download the log as a CSV file. The sample game shows the whole screen on a demonstration game with made-up players.

• It estimates velocity from video. The numbers are AI estimates, not readings from a radar gun, and it does not replace one.
• It does not produce a box score. It is a pitch log, not a scorebook.
• It does not chart the game live. The log comes after you upload the video.
• It does not know names on its own. Names come from your roster, matched by jersey number, so players who are not on a roster may appear without names.

It replaces the hand-kept pitch chart, not your velocity hardware. Every pitch in the log is timed to the video, so you can check any row against the film.

The video has to show every pitch from behind the plate. How to film a game for analysis covers the camera position, the framing and the file the upload accepts.