Click two points on the pitch to draw a temporary arrow, then specify event details and click 'Add to Pitch'. Your temporary line will be replaced with a chalk one.
You can add as many lines as you like.
'Player Position' and 'Opponent Position' are represented by single points drawn at the line's origin.
Delete a line by double clicking on its origin.Click for more detailed instructions.
Hints and Tips
You don't have to label every mark. If the board is getting cluttered, you can use un-labelled points for opposition players etc.
The chalkboard works on mobile too! (Although you might not be able to double click to delete points). Why not try it live from a game?