Ask anyone in the theater industry with a horse in the awards-season race, and they’ll tell you that the Tony category for best musical — or any of the four major awards for overall productions — are limited to just four contenders apiece.  But that could all change this year.

In a meeting last month, the Tony Awards administration committee quietly voted to allow the option of expanding one or more of the four show categories (musical, play, musical revival and play revival) to five nominees, if nine shows or more that season are eligible to be considered in a given category.

In the new rules, going from four to five nominees will only happen if, in the nominating process, a fifth show achieves a vote tally that would put it in the same ballpark as  the show with the fourth highest total. Final decision will be made by the accountants totting up the votes of the nominating committee.

It’s not quite as extreme as the Oscar expansion of the best picture nominations list from five to as many as ten. But the inclusionary impulse is the same — and it might actually happen this year for what’s widely considered the only Tony to move the box office needle: new musical.

The 2013-14 slate of new musicals encompasses “First Date,” “Soul Doctor,” “Big Fish,” “A Night with Janis Joplin,” “After Midnight,” “A Gentleman’s Guide to Love and Murder,” “Beautiful,” “The Bridges of Madison County,” “Rocky,” “Aladdin,” “If/Then” and “Bullets Over Broadway.” That’s 12 right there, and that’s no even counting Off Broadway alumna “Violet” and “Hedwig and the Angry Inch,” which could theoretically be classified as new because neither has ever appeared on Broadway. It also doesn’t count the recently added “Lady Day at Emerson’s Bar & Grill,” which bills itself as a “musical play.”

“The number of shows eligible for the Tony Awards, both in the new and revival categories, will now vary based on the number of productions that open each season,” said a statement from Tony Awards Prods. “The Tony Award Administration Committee’s new ruling allows the Nominating Committee the flexibility to acknowledge the best of each season’s eligible shows.”

In the new rules, there’s also the chance to reduce a show category to as few as three nominees, if five or fewer productions in that class qualify for nomination consideration.

A five-title race is also a possibility in the play revival category this season, which has yielded a robust crop of starry revivals including “Romeo and Juliet,” “The Winslow Boy,” “Betrayal,” “Twelfth Night/Richard III,” “700 Sundays,” “Macbeth,” “No Man’s Land/Waiting for Godot,” “Machinal,” “A Raisin in the Sun” and “Of Mice and Men.”

Just as the Oscars loosened up the best picture category in an attempt to acknowledge a broader spectrum of worthy film work (and potentially expand the box office boost from awards-season attention), the Tonys also aim to recognize the broadening scope of Main Stem fare and, while they’re at it, showcase one more production during a nationally televised awards ceremony that serves as a prime marketing opportunity for individual shows and for Broadway overall.

Tony Awards tradition used to allow on-air performance segments for only those productions nominated for a major show award. More recent years, however, have incorporated segs from older, more familiar productions as well as from some of the season’s prominent shows left out of the major nominations.

The Tony acting races have long included five nominees a piece, but all others, including directing laurels and design kudos, remain set at four.

Although the new rule is now in place, it’s still not certain the nominating process will result in the expansion of any of the show categories to five titles. With a slew of productions yet to open before the April 24 eligibility cutoff, Tony noms are due to be announced April 29.