One thousand two hundred and thirty seven.

This number, no matter how it may seem, is not arbitrary. This is the number of delegates needed to win the Republican Presidential Nomination outright. In other words, before the convention starts, a candidate needs to get 1237 delegates, outright, before the delegates come into play.

First, let me give you some background information. All states, via voting in primaries and caucuses, can choose a winner, who then gets a number of delegates to be bound to that candidate at the Republican National Convention, to be held in July. That number of delegates is directly proportional to the number of registered Republican voters that that state has. So, Florida has 99 delegates, and Pennsylvania has 72. In Florida, then, the winner would get 99 delegates pledged to them at the convention. However, some states allocate their delegates proportionally. In Iowa, where there are 30 delegates, if Mr. Trump had 40% of the vote, Mr. Cruz also had 40%, and Mr. Kasich has 20%, then Mr. Trump and Mr. Cruz would get 12 delegates each, and Mr. Kasich would get 6 delegates.

In some states, delegates are picked beforehand and are then pledged to the candidate who wins. In some states, voters pick the delegates and the delegates, in turn, vote for the candidate whom they support. And in still others, candidates pick their delegates. But no matter who the delegates are, the delegates are bound at the convention in July.

So why does all of this matter? Because if by the time voting wraps up in California on June 7, if no candidate has more than half of the 2472 delegates, which is 1237 delegates, than the Republican delegates can vote on their own. Therefore, it can be very important to get every single delegate vote. At this point, with 734 delegates remaining up for grabs, Donald Trump has 845 delegates, Sen. Ted Cruz has 559, and Ohio Gov. John Kasich has only 147. To clinch the nomination, Mr. Trump needs to win 392 out of 734 delegates, or 53.4%. Cruz needs 678, or 92.4%, and it is impossible for Kasich to win without a contested convention.

Obviously, Trump is the only candidate with a real chance. Will he get there, or no? That is going to be a very important issue leading up to the final day of voting in California on June 7. Using a stimulated formula based on polls in all states to vote from here on out puts Trump just barely under the magical 1237 bar, with 1234 delegates. But polls aren’t perfect, and still anything can happen.

Many political experts predict that Trump won’t get there. “Trump won’t win unless a political asteroid falls in California, and even that may not be enough”, says Hugh Hewitt of CNN. “Trump will need 119 of the 172 delegates in California, and he probably won’t even get 100”. Other experts have predicted 1210, which is close but not there.

After California votes on June 7, we will know the answer. But until then, we will not know, and another estimation has put him at 1289. So what will happen?

Next week brings the Indiana primary, and another update on the Donald’s road to 1237.