The nominations appear to be determined by a mathematical formula, rather than a . According to rules which the nominating committee must follow, "When there are nine or more eligible shows in a Best Show category, at the Tony Nominating Meeting, the Nominating Committee will be instructed to cast one vote each for four eligible shows as nominees on his/her secret ballot. Such ballots shall be collected and tabulated by a representative of the Accounting Firm." With twelve new musicals, ten new plays, and fifteen play revivals this season, there were definitely enough to put this rule into effect for all but the revival of a musical category.
Once the votes are tabulated according to the rules above, the four shows with the most votes automatically become the nominees. If the fifth-place show (the show with the fifth-highest vote count) is three votes or fewer away from the fourth place contender, then and only then is there a fifth nominee in the category. This way, in a season with not many new plays or musicals, the committee is not obligated to inflate the slate out to 5 nominees, but in a crowded year like this one -- with several contenders in a tight race -- a fifth nominee can enter the race in a contentious year. What does this mean for the 2014 nominees? It means that the Best Play race was a tight one -- the fourth- and fifth-most voted for plays amongst the committee were within three votes of each other. But in the Best Musical and Best Revival of a Play categories, the competition was not that steep -- only the top four got in because nothing else was close enough to sneak into that fifth spot.
There is an entirely different rule, however, that caused there to be only three nominees in the Best Revival of a Musical category. That rule states, "When there are five or fewer shows eligible in a Best Show category, at the Tony Nominating Meeting, the Nominating Committee will be instructed to cast one vote each for thee eligible shows as nominees on his/her ballot." The result here would be that the top three vote getters would automatically become nominees, and there would only be a fourth nominee if the fourth-place vote getter was within three votes of the third place one.
Now that we've gotten that clarified, I'm going to go back to the grind and work on my first round of predictions on who will WIN the Tony's this year.