What is the repetition in Casey at Bat?

There are many examples of repitition in "Casey at the Bat." Here are some examples:

- "There was ease in Casey's manner as he stepped into his place" (line 1)

- "There was pride in Casey's bearing and a smile on Casey's face" (line 6)

- "Then while the writhing pitcher ground the ball into his hip" (line 25)

- "Now Casey stood a-sawin' and a-sawin' at the plate" (line 34)

- "But there is no joy in Mudville--mighty Casey has struck out" (line 40)