Du kan också lägga summan i en fallsats, där fallet utvärderar det andra villkoret, och sedan bara summera dessa poster där villkoret är sant...
SELECT m.member_id, m.teamname,
Sum(Case When r.track_Id = '$chosentrack'
Then total_points Else 0 End) TotalChosenTrackPoints,
Sum(Case When r.track_Id < '$chosentrack'
Then total_points Else 0 End) TotalLessThanChosenTrackPoints,
total_points as last_race_points
FROM members m
Join members_leagues l
On l.member_id = m.member_id
Join member_results r
On r.member_id = m.member_id
Where l.league_id = '$chosenleague'
And l.start_race = '$chosentrack'
Group By m.member_id
Order By r.total_points Desc,
last_race_points Desc, m.TeamName Desc