Why is Tianjin dialect very similar to Xuzhou dialect?

However, in modern times, a large number of Tianjin immigrants came from the central plains mandarin area in northern Anhui, and the local dialect in Xuzhou was similar to that in northern Anhui itself.

The prototype of Tianjin dialect is Huaixi dialect in Ming Dynasty, which originated between Suzhou and Guzhen County in Fengyang Prefecture and between Xinbang dialect and Xuhuai dialect in Central Plains Mandarin. Fu Shang, Xinbang and Xuhuai dialects, which belong to the Central Plains Mandarin, have the same pronunciation except for a few words and can be regarded as the same dialect area. It is normal to have a high degree of similarity.