How to make a formula/function look at the most recently inputted cells

Hi Everyone,

I am creating a workbook of football scores that I will be updating weekly (or after each round of Premier League games is played.) I currently have made a sheet with team names in column A and also in row 1, making a kind of matrix which will show all the scores. I want to be able to calculate each team's current form (looking at last 6 games) by a simple average of their scores. The problem is my table is not in chronological order. Not sure if I have provided enough information here as this is my first post.

I will also be making another table looking at goals scored/conceded/points for each game, but the 'Team by Team' matrix will very much be the master sheet as I only want to input the most recent scores and for the rest of the sheets to update from that.

Thanks in advance for any help

Craig