Between 1917 to 1920, what are the names of the team who ranked first in the first half of the season each year?
year BETWEEN 1917 AND 1920; first half of season refers to half = 1
SELECT DISTINCT T2.name FROM TeamsHalf AS T1 INNER JOIN Teams AS T2 ON T1.tmID = T2.tmID AND T1.year = T2.year WHERE T1.half = 1 AND T1.rank = 1 AND T1.year BETWEEN 1917 AND 1920