Table: chas_mortimer_1969
Columns: year
class
team
points
wins

Question: What class is after 1973 with 41 points?
SQL: SELECT "class" FROM chas_mortimer_1969 WHERE "year" > 1973 AND "points" = 41

Question: How many wins for bikes with under 54 points, team yamaha, a 250cc bike, and before 1977?
SQL: SELECT COUNT("wins") FROM chas_mortimer_1969 WHERE "points" < 54 AND "team" = 'yamaha' AND "class" = '250cc' AND "year" < 1977