A few poems may get cut right away, but only if the most distinctive quality is an obvious lack of skill. A second reading involves feelings with unusually appealing poems rising to the top. However, emotions evoked by sloppy work, offensive words, or unwelcomed subject matter work against a poem, making it harder to gain higher placement as the readings progress. Subsequent readings shuffle each poem's placement. It's like the Olympics when a gymnast's technical skill and fluid motions increase the score.
Some poems receive lower placement because they go on too long to sustain interest.
Some have therapeutic value for the poet but exclude other readers. A children's poem may not be appropriate for young readers, especially if it ends with a cynical view or ironic twist. A beautifully written poem may suddenly get preachy, or a technically correct piece may have nothing interesting to say. Conversely, poems receiving greater attention show precision and musicality in word choices, a workable style for an interesting topic, and a fresh point of view. Such poems often provide an engaging story or a highly observant comparison.