Before revision:  We further analyze the distinct behaviors of the two approaches, and show that fusing their output reduces the performance gap (measured in NDCG@3 ) between the manually-rewritten and automatically-generated queries to 4 from 22 points when compared with the best CAsT submission .
After revision:  We further analyze the distinct behaviors of the two approaches, and show that fusing their output reduces the performance gap (measured in NDCG@3 compared to the best submission of TREC CAsT 2019.