The financial burden of renting the County Ground had a significant impact on Southampton F.C., particularly during the late 20th century. Here are some key points regarding this situation:

1. High Rental Costs: Southampton F.C. rented the County Ground from the local council, which imposed a substantial financial strain on the club. The rental fees were high, and this cost was a significant part of the club's operating expenses.

2. Limited Revenue Generation: The club's ability to generate revenue was hampered by the rental agreement. Unlike owning their own stadium, which would allow for more control over matchday income and other events, renting limited the club's financial flexibility.

3. Impact on Investment: The financial burden of renting meant that less money was available for player acquisitions, wages, and other investments necessary for competing at higher levels. This could have affected the club's performance on the pitch, as they struggled to attract and retain top talent.

4. Stadium Move: The financial pressures ultimately contributed to the club's decision to move to a new stadium. In 2001, Southampton F.C. moved to St. Mary's Stadium, which they own. This move was aimed at alleviating the financial strain of renting and allowing for better revenue generation through matchday sales and events.

5. Long-term Financial Health: The transition to St. Mary's Stadium has been beneficial for the club's long-term financial health. Owning their own ground has allowed Southampton to invest more in the team and infrastructure, leading to improved performance and stability.

In summary, the financial burden of renting the County Ground significantly affected Southampton F.C. by limiting their financial resources, impacting their competitiveness, and ultimately leading to a strategic move to a new stadium that has allowed for greater financial autonomy and growth.