What is four and a half sentences?

Is it three and a half sentences? Four and a half sentences have never been heard.

Three sentences and a half is a traditional folk art performance form in China. Each paragraph has three long sentences and half sentences. Generally, four people perform, three people say three long sentences, and finally 1 person only says half sentences of two short words, so it is called "three and a half sentences". Three sentences and a half are generally rhyming, homophonic and humorous, and are deeply loved by the masses.