Do you have a table for the teams and a relationship like:
Teams::TeamID = Games::WinningTeamID
Thanks for your reply. I may have exaggerated: I have a single table not a "database." In other words, the answer to your question is No.
Well, having such table would certainly help - and not just with the current issue.
As it is, you could define a self-join relationship (using another occurrence of your one table) as:
Games::HomeTeam = Games 2::WinningTeam
Then a calculation field =
Count ( Games 2::WinningTeam )
will return the number of wins of the home team in the currently viewed record (no find is necessary for this).
Is that to say that unlike SQL where I could search for records where Home Team = Winning Team, I cannot do this (directly) in FM?
Of course you could: for example, you could create a script such as:
Set Variable [ $homeTeam ; Games::HomeTeam ]
Enter Find Mode 
Set Field [ Games::WinningTeam ; $homeTeam ]
or do the same thing manually.
But if your purpose is to find out how often the home team won, a relationship can fetch that data "live" without leaving the current record. Note that in the find the current record will be omitted, if the home team did not win that particular game.