The longest and most exhausting masked ball in Israel's history - what Likud briefing sheets termed "talks on passing a responsible budget" - ended as expected on Tuesday, with Prime Minister Benjamin Netanyahu announcing early elections.

Actually, Netanyahu made this decision six months ago, but then he blinked at the last minute - and lived to regret it. He never really tried to pass the budget, not because he didn't want to, but because he knew the chances of succeeding were near zero. But he did want to reach this point in time, on the eve of the winter Knesset session, perceived as someone who had done his darnedest to pass a responsible budget.

And have we mentioned Iran yet? Iran and a responsible budget - security and the economy - are the two cornerstones on which Netanyahu is building his campaign.

Netanyahu knows what every political correspondent reiterated last night: His starting point in these elections is excellent, for three reasons. First, there are no other serious candidates for prime minister. Second, since the last elections, the Likud/right-wing/religious bloc has never lost its majority; polls have consistently shown it at between 64 and 68 Knesset seats (out of 120 ). Third is the split in the center-left bloc. Only a dramatic development in the next three months (assuming the campaign doesn't drag on for longer ) is liable to change this picture.

Are you looking for drama? Here's one scenario for a game-changing event: a last-minute merger in which some or all of the center-left parties form a joint list that could pull votes away from Likud and then demand that President Shimon Peres give it first crack at forming the next government. At the moment, this isn't in the cards: Yair Lapid promised last night that his Yesh Atid party would run independently all the way to the finish line.

But what if former Prime Minister Ehud Olmert defied all expectations by returning to politics - despite both the pending appeal of his acquittal on charges of receiving cash-filled envelopes from businessman Morris Talansky and his ongoing trial on charges of taking bribes in the Holyland corruption case? Or what if former Kadima chairwoman Tzipi Livni were to reenter the ring? With either Olmert or Livni in the race, Lapid would no longer be such a superstar. He would have to choose between winning a mere handful of seats or joining forces with them to avoid being accused of foiling the chances of replacing Netanyahu.

Both Olmert and Livni are considering it, and will have to make up their minds in the next few days. Olmert's situation is more complex: He wants badly to return, but recognizes the hurdles. Quite aside from the possible outcome of the Holyland trial and the Talansky appeal, is he even eligible to serve as prime minister while he is a defendant in both? Only the High Court of Justice can answer this question.

It's hard to see Olmert running when it's not clear he could be prime minister even if he managed to put together a coalition. But on the other hand, as noted, he's dying to return.

A unification of the center-left bloc is the main scenario keeping Netanyahu awake at night. To forestall the danger, he is preparing a fitting response: a merger between Likud and Avigdor Lieberman's Yisrael Beiteinu party. That idea initially arose back in May, when Netanyahu first decided to call early elections, before he abruptly backtracked and brought Kadima into the coalition instead. Now it's resurfacing. And if that's what is needed to ensure that Netanyahu gets the nod from the president to form the next government, it will happen.

Assuming no drama occurs, however, the main question during the campaign will be what Netanyahu's third government will look like. Lapid has already said he wants to be a minister in the next government. Labor chairwoman Shelly Yacimovich has consistently, and justifiably, refused to rule out joining a Netanyahu government. It's clear that Shaul Mofaz's Kadima party - or what is left of it - would also be a partner in such a government. And that's not even to mention Likud's natural partners: Yisrael Beiteinu, Shas and United Torah Judaism.

In other words, every party except Meretz and the Arab parties is a potential member of the next government. Clearly, they won't all end up there, but it will be amusing to watch them fight over their place in line.

But before the fight between the parties comes the fight within the parties. Likud's primary is shaping up to be a slaughterhouse: Seven to nine sitting MKs are expected to be dropped from its next Knesset slate. In contrast, Labor - which polls show winning 20 seats, up from eight currently - will have plenty of room for new faces. As for Kadima, Mofaz might yet seek to cancel its primary and dictate the party's slate himself.

Kadima, in fact, is one of the great question marks of the next election. Four years ago, it was the ruling party, and in the 2009 election, it won the most seats. But will it still even exist after the next election? And if not, where will most of its MKs end up?