Hi Garthwaite, Ken Sproat in his book on the history of Blyth Spartans writes on formation in 1899 Spartans played on a ground, at Percy's gardens near where Cypress gardens and Middleton street intersect. In 1901 they moved to the North Pit ground (bates) that pitch which was known as the "Spion Kop" is now covered by Chestnut Avenue and Poplar Avenue.
In the 1905/06 season, Spartans played at a ground that was, directly over the road from the southern end of Croft Park. They played at this ground for only one season, as the area had been earmarked for development and it was at this ground they played the charity friendly against Newcastle. He says the western halves of Hedley avenue and Hunter avenue and the northern portion of Shotten avenue cover the site.
In 1906 Spartans moved to a ground called, Thoroton cottage, now covered partially by Broadway circle and the western end of Princess Louise Road, before moving to their current home Croft Park in 1909.
Kens book is available from the Spartans online store
https://bsosc.myshopify.com/collections/all?page=5