my new version is:
UPDATE tblSchedule
SET tblSchedule.HomeScore = 14,
Schedule.AwayScore = 17
FROM tblSchedule
INNER JOIN tblTeams AS HomeTeam
ON tblSchedule.HomeTeamID = HomeTeam.id
INNER JOIN tblTeams AS AwayTeam
ON tblSchedule.AwayTeamID = AwayTeam.id
WHERE tblSchedule.gamedatetime = '2005-12-20 14:00:00'
AND HomeTeam.FirstName = 'New England'
AND...