Quoted in Sporting News, 7 Aug. 1971. Berra says in The Yogi Book (1998) that he was referring here to the difficulty of playing left field in Yankee Stadium in late autumn when "the shadows would creep up on you and you had a tough time seeing the ball off the bat."
Prentice Mulford (2015). “The Prentice Mulford Premium Collection: “New Thought” Studies, Novels & Memoirs: Thoughts Are Things, The God In You, Your Forces and How to Use Them, Life By Land and Sea, Swamp Angel and more (Wisdom & Empowerment Series)”, p.441, e-artnow