Is there a way to automatically work out stats based on wins and losses in a table

bIG pOTS.xlsx
Im looking to create an excel spreadsheet for our pool team. Someone had done this for us and left without giving us the functionality.

For each game week there is 2 halves and I needs add a W if they won or L if they lost and nothing if they didnt play in that half. The excel sheet can then highlight green if its a W or red if its an L.

At the bottom it will work out the percentage of games won for each player.

At the top it will work out the percentage just based on the last 6 games.

Is this possible with Excel or may he have been using a different programme?

Thanks in advance.