Everything about the accuracy of a conversion is decided before the upload. The model reads what the photo contains; it cannot recover a move that a shadow ate or a fold cut in half. This page is about the input side — what makes a photo convert cleanly, and how to tell in five seconds whether to reshoot.
The four things that decide it
Light, evenly. Daylight near a window beats any lamp. The specific failure to avoid is your own shadow: leaning over the sheet with a phone puts a dark band across exactly the columns you care about. Step to the side of the light instead of between it and the paper. Flash is worse than no flash — it burns a white disc into the middle of the sheet.
Flat. A scoresheet that has spent the afternoon folded in a pocket will have creases straight through the move columns, and a crease breaks the strokes of a letter. Press it flat under two books for a minute before you shoot. Reverse-fold a stubborn one.
Square on. Hold the phone parallel to the paper, not tilted across the desk. A tilted shot compresses the far end of the sheet, and compressed rows are where column alignment starts to slip — white's move drifting into black's column.
Filling the frame. All four corners inside the edges, and nothing else. Table around the sheet is wasted resolution: every pixel spent on wood grain is a pixel not spent on a letter.