[1] He became a marker, a role that involved keeping the score of billiards matches, at the Angel Hotel, Sheffield, at the age of 13.

[2][3] In October 1887, Peall and Mitchell played at the Royal Aquarium in a 15,000-up match advertised as the "All-in Championship."

The second of these unofficial matches was staged in March 1888 at the same venue, and this time Peall won by a large margin, 15,000–6,753, including a record break of 2,031.

[4][5] Mitchell won the first of three "Championship of the World" tournaments promoted from 1889 to 1891 by billiard table manufacturers George Wright and Company, finishing behind Peall in the other two.

[5] During his career, Mitchell compiled over 1,000 four-figure breaks the highest being a 1,620 which included 536 consecutive pots of the red from the spot.