Final answer:
The line from the poem aims to create suspense and drama, possibly misleading readers into believing that Casey has hit the ball and building up the emotional stakes of the narrative.
Step-by-step explanation:
The line 'And now the air is shattered by the force of Casey's blow' is likely designed to create suspense and drama in the poem. This phrase is a classic case of leading the reader to anticipate an event, in this instance, making the reader think that Casey has hit the ball.
However, this line can also serve as more than just a suspense creator; it can be seen as a misdirection, encouraging the reader to believe that something spectacular has happened only to be followed by an unexpected outcome, such as Casey's failure. The specific selection also underlines the importance of word placement and choice in poetry, as well as how these elements can generate strong imagery and emotion.
Despite the temptation to associate the line with a particular poem structure like a Spenserian Sonnet, it is more likely that the line intends to involve the reader emotionally in the action of the story rather than it fitting into a complex meter or serving as a denouement.