ทีมที่เริ่มในปี 1950 คว้าแชมป์ได้สำเร็จได้อย่างไร?ไม่จำเป็นต้องใช้โต๊ะทั้งหมด
How may championships were won by the team that started in 1950?It is not neccessary to use all the tables.
 table_21564794_3:  championships_in_st_louis [ VARCHAR]  began_in_st_louis [ VARCHAR] 
SELECT championships_in_st_louis FROM table_21564794_3 WHERE began_in_st_louis = 1950