How to film a baseball game for analysis

• One video of the whole game, filmed from behind the plate.
• An MP4 or MOV file, up to 30 GB.
• One file for each game. The upload page takes a single video file.
• Any camera or phone. No special mounts or sensors are required.
• A laptop to upload it from. Uploads go up in small chunks and resume if your connection drops.
• A roster is optional for your first game. From the second game on, the team needs at least 9 players on its roster.

Most games are ready in 10 to 20 minutes. Softball games are filmed and uploaded the same way, and the softball page says what else a softball staff should know.

Put the camera behind the backstop, on the line that runs from the pitcher through the middle of the plate. From there one frame holds the pitcher, the batter, the catcher and the plate for every pitch, and the ball travels toward the camera instead of across the picture.

Set it high enough to see the pitcher over the catcher and the umpire. If you cannot get the height, move a step to one side, so that the umpire does not hide the pitcher’s release.

Turn the phone on its side and film in landscape. Set the frame before the first pitch: the pitcher, head to feet, near the top of the picture, and the plate with both batter’s boxes near the bottom. Leave some room on each side for a pitcher who works from either edge of the rubber.

Then leave it alone. Do not follow the ball after contact and do not zoom in on a hitter. The video is for charting pitches, and every pitch starts and ends inside that one frame.

A tripod behind the backstop or a mount that clamps to the fence both work. A camera held by hand drifts over a full game, and the person holding it watches the game instead of the picture.

With a chain-link backstop, put the lens right at an opening in the fence, so that no wire crosses the picture. A fence a few inches in front of the lens puts wire across the strike zone, and the camera may focus on the wire instead of the pitcher.

• Start with a full battery, and bring a battery pack if the phone is not new.
• Check the free space before you leave home. A full game is a large file.
• Silence calls and notifications, so that nothing interrupts the recording.
• Press record before the first pitch and stop after the last out. Do not stop between innings.

Higher resolution and a higher frame rate make a bigger file. The limit the product sets is on the size of the file, 30 GB, so check the size of one game before you film a weekend of them. Some cameras split a long recording into several files. The upload takes one file for each game, so join the parts on your computer first.

• The camera moving: a tripod that gets bumped, or a phone carried from one spot to another.
• Zooming in the middle of the game, which changes the picture for every pitch after it.
• A chain-link fence too close in front of the lens, with wire across the pitcher or the plate.
• Filming in portrait, which cuts off the batter or the pitcher.
• A battery that runs out, or a phone that fills up, in the fifth inning.

Copy the file to a laptop and upload it on this site. How it works has the four steps from the field to the review screen, and the sample game shows what the finished log looks like, on a demonstration game with made-up players. In the log of your own game, the velocities are AI estimates from video.