If some of the Helium discussion board postings (as I write this in April 09) are any indication, it looks the question "How to get your leapfrog approved in Helium" is not an easy one to answer.
You essentially resort to leapfrogging your Helium article under the following conditions:
1) You have noticed several typos (which far outnumber 3 or 4 that you can get corrected by requesting a typo correction to content@Helium.com in your article.
2) You find some grammatical mistakes and some other simple, not too glaring mistakes (like poor formatting or a few poor punctuation marks) that you failed to notice earlier; you want to set them right, so that your article looks truly professional.
3) You have some genuine mistakes in your article; you have some added information that can improve your article's content and worth; you want to embellish your article with more powerful and attractive statements that will enthuse the reader the article "fully". So, you go ahead and do a leapfrog, irrespective of its current rank.
4) You do some or all of above to improve the rank of your article which is found tanking.
After you submit your leapfrog, what happens at Helium?
Your leapfrogged article is presented to a minimum of 3 raters along with your old article for comparison and judgment to decide which one is better or whether they are "almost same". Unfortunately, at the time of my writing this article, Helium does not provide any identification as to which is the old version and which is the leapfrogged version to the rater.
If at least two of the three raters click "same" button or if they choose the improved version to be the better one, the leapfrogged article gets through and it replaces the older one. Here comes the subjectivity, keenness of rating or callousness of a rater into the picture.
There are broadly 3 types of raters:
1) Those Who Know Clearly How a Leapfrog Works:
They glance at top of the screen to know that it is a leapfrog that they are rating and they are aware of the existence of the "same" button for use in this case. They also know that hitting the "same" button will pave the way for the acceptance of the leapfrogged version. As long as there is no nonsense found in the two comparative articles, they know there is really no need to read through the entire article and sit in judgment. They know the author knows better why he/ she leapfrogged. They hit the "same" button and proceed to the next rating.
If your leapfrogged article is rated by such persons, you are safe. The leapfrog gets approved!
2) Those Who are Relatively New to Helium (or Those Who are Ignorant or Too Casual)
They rate mechanically. They do not even notice many times that it is a leapfrogged article that is under rating. They tend to rate the articles in no way different from rating OTHER articles. They probably fail to notice the existence of "Same" button. If they are conscious enough to notice it, they may hit "same" the button, if both the articles' contents look more or less same. They may not even be aware that hitting the same button will get the leapfrogged article through.
Some "speed raters" too may fall into this category. They are in a hurry to snatch their missing rating star at month end! So, they may be clicking at random to the left or right without even glancing at the articles!
If your leapfrogged article gets rated by such persons, it may get approved or rejected purely based on your luck!
I have personally seen recently one of my "almost same looking" article getting rejected in leapfrog! It is obvious that my leapfrogged was judged by the above category!
3) Those Who Rate Articles Like a Supreme Court Judge
They know they are rating a leapfrogged article. They will sincerely read through both the versions word by word, even if both look almost same. They will make their well judged decision based on their criteria of quality - content, formatting, grammar, typos, whatever. They don't believe in the dictum that if the author has leapfrogged, he knows better why he did it. They would say, "No. I know what is real quality that he may not know. I am duty-bound to deliver my honest judgment".
If your leapfrogged article gets rated by such persons, your chances are fifty-fifty! If your leapfrogged article is almost similar to the original, it may get through. If it is considerably revised, then it depends on whether the raters' perception and yours are going to be in sync or not.
You might have removed a paragraph to make your article short and sweet; the rater may feel the existence of the extra para added more weightage! You might have added a humorous introduction to your article to make it breezy! Your rater might not get bemused by it!
So, the answer to the question how to get your leapfrog approved is - "it depends!"