I like this rule, but I think you could introduce it further. I agree that the first sentence of this paragraph is a bit confusing. When introducing your rule you could try saying "my style rule" instead of "the style rule" so that it is clear what rule you are discussing. You do this in the next paragraph, so maybe just start it earlier to keep it consistent.

Explanation of my rule involves proficiently inserting a parenthetical phrase into a sentence and using commas to separate the phrase. I arrived at the rule because of much misuse involving simple comma usage, whether the comma is not used where emphasis is needed, or whether the comma is used too much, causing the reader to constantly pause and think of each connecting expression in a sentence. If a paragraph contains too much overuse or underuse of the commas, the flow concludes choppy or endless. (Before this paragraph would be a good place to give your style rule. It would introduce this paragraph and give the reader a better understanding). <-- Yes. agreed.

An example of a parenthetical expression in a simple sentence set off by commas is used in the Elements of Style book: “The best way to see a country, unless you are pressed for time, is to travel on foot.” (need page number for citation)This parenthetical phrase “unless you are pressed for time” has changed the meaning of the sentence for the reader. If the phrase is left out, the reader may think the only real way to see the country is on foot – to walk! Another example Strunk and White uses to show how the absence of just one comma in a rather simple sentence changes its meaningMaybe say, "Here is another example..." Or add "is" before the quote, it doesn't introduce it correctly: “Marjorie’s husband, Colonel Nelson paid us a visit yesterday.” There is no justification for neglecting even one comma in the parenthetical subject Colonel Nelson. We know that “Colonel Nelson paid the visit”, but “Marjorie’s husband” remains outside of the sentence and interrupts the flow of the sentence. (You should put the correct form of the sentence). Make sure you cite the page numbers of the examples you use.

Another longer parenthetical phrase seems to shift meaning just by the absence of a comma: “My brother(wait, shouldn't there be a comma after "my brother"?) you will be pleased to hear, is now in perfect health.” Verbalizing this sentence seems like a short run-on and once again, interrupts the flow of the meaning about the brother to the reader. The original rule of comma usage with parenthetical words or phrases not only entails word usage, but also dates. When using dates, parenthetical words or figures are set off by commas. In these examples from Strunk and White, one or two commas may be used to place emphasis on the dates for the reader to grasp: February to July, 1992; April 6, 1986; and Wednesday, November 14, 1990. Leaving out a comma in these examples limits the reader from the sense of the date order. The authors do believe, however, that by rearranging the date information, commas can be safely omitted. Their example: 6 April 1988. This example, they believe, provides an acceptable way to write a date because the reader can quickly grasp the words and figures. Once the writer considers the classification of a parenthetical phrase or word into a sentence, commas provide better emphasis and meaning to the reader.(I would rework this sentence, I had to read over it a couple of times). Identifying what is a parenthetical phrase is critical to such comma usage as well.

Parenthetical words, like titles and abbreviations, always use commas in order to separate the direct emphasis on someone’s title. For instance, “Well, Susan, this is a fine mess you are in.” provides commas for Susan’s name to allow the writer to address the reader correctly. Abbreviations for etc., i.e., and e.g. and degrees and titles are parenthetical and need to be offset by commas. “Letters, packages, etc., should go here.” And “Rachel Simonds, Attorney” are two models needing commas for direct emphasis of the subjects. Etc. with a comma intends for the reader to stop thinking about the subjects and move on with the action.

In contrast to using a sentence with a person’s classification, no commas are to be used. “Billy the Kid” or “The novelist Jane Austen” are identified by their noun in combination with a restrictive term of identification, and thus a comma is not necessary. Another example the author gives in leaving out the comma is for the use of “Jr.” If Jr. is abbreviated and used in a simple sentence, a comma can mistakenly be placed after the abbreviation. However, the comma rule does not apply here because Jr. is used restrictively as in “James Wright Jr.” Logic, the author claims, evokes one to eliminate the comma here. The next set of examples from the author(The author of what?) on the comma use in parenthetical expressions of a sentence result in the use of nonrestrictive relative clauses, clauses that introduce conjunctions that specify time and place. In speaking about nonrestrictive relative clauses, the author explains in Strunk and White that the clause stands alone; it does not distinguish the antecedent noun in the sentence so a comma is needed. The author's example states, “The audience, which had at first been indifferent, became more and more interested.” And “Nether Stowey, where Coleridge wrote The Rime of the Ancient Mariner, is a few miles from Bridgewater.” The commas are placed in the parenthetical expression that “which, when and where” are used in a nonrestrictive phrase. These words do not take away from the meaning or provide any limitations to the context of the sentence; they only complement the sentence. Restrictive clauses require a different handling in a sentence. They are not parenthetic, so no commas are used. “People who live in glass houses shouldn’t throw stones.” gives the reader understanding of the people, and the understanding that the sentence would not be divided into two independent sentences. (This Paragraph contains a lot of info. I would break it into two different paragraphs). Make sure you are explain/introduce the text you utilize in this paragraph.

Conversely, I don't know if "conversely" sounds quite right here..maybe try something more simple like "On the other hand" or "On the contrary." if the main clause comes before a subordinate clause, then a comma would be used: “Our oldest daughter, Mary, sings.” The authors(Again, which authors?) suggest identifying the clauses, whether they are restrictive or non-restrictive, and then applying the commas to provide emphasis. In Williams’ Style Toward Grace and Clarity do not(He does not directly..) directly describe this rule of comma use, but it does provide advice in chapter 4 of emphasis, to manage ideas so that they flow coherently for the reader. Williams describes how to rearrange subject and verb information much like that of parenthetical expressions in either the beginning, middle, or ending of a sentence which will ultimately give different emphasis on the ideas.

One example involving comma use that the author(?) says to completely avoid is in the role of a metadiscourse. Writers need to use metadiscourse sparingly, and the author prefers an expression be placed in the middle of the sentence in between commas, like this example: “The opportunities we offer are, it must be remembered, particularly rich at the graduate level.” The emphasis does not bring down the rest of the sentence to take away what rich opportunities are at the graduate level. (Since we are writing toward a larger audience outside the classroom, you may want to explain what metadiscourse is)

Commas provide balance in sentences when used appropriately and give the reader the chance to understand the flow of ideas and their connections to parenthetical statements. It is the hope that this essay provided simple comma application involving parenthetical statements, whether in word or phrase, to specify subjects and their actions in a clear and cohesive sentence. I would try explaining more the overall benefits of the rule you came up with and once again, avoid the talk about the essay directly in your actual essay--let it speak for itself.

I Think that you have a lot of great information here, but it just needs a little more clarity. Be sure that you are stating where the information that you have is found. Saying "the author" doesn't tell an outside reader who you are tlking about. I would also consider the outside readers in the beginning of your essay. Be more clear about your rule. It would be a good opening pargraph, then maybe copy your rule into the essay. Those of us in the class know what your talking about, but others won't. Overall, I think you are off to a great start, just a little fine tuning:)

You have a good start here. Just make sure you are being thorough in all areas of explanation. Sometimes you give an example of either the right or wrong structure of the sentence, when it might help if you gave both. It could better illustrate what you are trying to say in the description after the example. Also, you might want to go more in depth in the initial introduction of your rule. Good work so far.