I have been trying to decipher a freebie excel workbook. It is not locked so free to play with to my hearts content.

Can anyone decipher this for me?

=SUMIF(Results!C:C,'Individual Tipster Profits'!A12,Results!L:L)

I have tried tracing precedents but points to what appears to be an empty cell Screen Shot 2016-03-08 at 20.22.12.png

I am a complete novice at this.

Thanks

Michael