He was nicknamed "The Mad Hatter" because of his habit of frantically tugging at the bill of his cap and re-adjusting it prior to every pitch as well as "Third Degree" for his penchant of giving up runs near the end of his career.
He gained the sobriquets "The Mad Hatter" and "Third Degree" due to his pre-pitch habit of adjusting his cap and his propensity for giving up runs in crucial situations later in his career.