Ultimately, elections come down to numbers.

So here are the numbers to keep in mind tonight:

TWO HUNDRED AND EIGHTEEN (218)

For all the talk about waves, landslides and tsunamis, the only number that really matters with regard to the fight for control of the US House of Representatives is 218. That’s a majority of the 435 seats that will be chosen today, and with it Republicans get the speakership and control of all the committees. Unlike the Senate, the House rules empower the majority at just about every turn. This gives the eerily tanned John Boehner the speakership, puts Wisconsin Congressman Paul Ryan (the author of the "Roadmap for America’s Future" plan to begin privatizing Social Security, Medicare and Medicaid) in charge of the House Budget Committee and California Congressman Darrell Issa ("We have to say to the Tea Party: You’re not strident enough, you’re not angry enough…") in charge of the Committee on Oversight and Reform. Issa will have the power to dog the Obama administration on every front with investigations, inquiries and hearings. And he will use it—whether his party has a one-seat majority or a fifty-seat majority.

TWO-HUNDRED AND THIRTY-THREE (233)

To get a majority, Republicans need only 218 seats. To rival the historic win of 1994, when Newt Gingrich’s "Republican Revolution" gained fifty-four seats and a claim on a mandate, the GPO must get to 233 this year. If Republicans fall short of that figure, Democrats get some space to make a comforting "it-wasn’t-so-bad" argument. If Republicans gain fifty-five seats or more, you won’t hear any talk about this being a divided country. They will resurrect the old claim that "this is a center-right country." And they might drop the word "center" this time.  But before they get going, it might be valuable to note that there have been significantly bigger midterm shifts: a fifty-five-seat pick-up Republican pickup in 1946, an eighty-one-seat pick-up for Republicans (from Democrats, Progressives and Farmer-Laborites) in 1938. Notably, in the presidential elections that followed each of these major shifts to the Republicans, Democrats (Bill Clinton in 1996, Harry Truman in 1948 and Franklin Roosevelt in 1940) won.

FIFTY (50)

The number to watch in the Senate competition is 50. If Republicans surf a major wave and win fifty seats—an unlikely but numerically possible prospect—the Senate will become a political chamber of horrors for both parties.

Republicans will put huge pressure on Connecticut Independent-Democrat Joe Lieberman and Nebraska Sort-of-Democrat Ben Nelson to switch parties. Pressure might also be applied to the last of the southern Democratic senators: Louisiana’s Mary Landrieu and Arkansan Mark Pryor.

If the Democratic caucus holds together, however, Vice President Joe Biden will cast the tie-breaking vote to organize the Senate as a Democratic chamber. That’s a big deal, as it means the party will hold control of committees. And if the Democratic leadership is willing to reorganize the chamber with an eye toward creating greater flexibility (with a shift in the cloture rules), the Senate could serve as an effective counterbalance to the House.

It makes sense to use the 50 figure as a touchstone because one scenario discussed here—with regard to the pressuring of conservative Democrats to switch parties—could play out even if Republicans only get to forty-eight or forty-nine seats. But the Biden-in-control scenario works only in an evenly divided chamber.

FIFTY-THREE (53)

Only if Republicans get to fifty-three senators are they in full charge of the chamber, as their party has moderate outliers who might work with the Obama administration on some issues—Mainers Susan Collins and Olympia Snowe, a potentially re-elected Lisa Murkowski from Alaska (who might sit as an independent) and a potentially elected Illinoisan Mark Kirk or a potentially elected Floridian Charlie Crist.

There are thirty-seven Senate contests this year; only by sweeping every one where their candidates are viable do Republicans get to fifty-three. Anything less empowers the GOP moderates, at least on social issues such as reproductive rights and LGBT rights.

TWENTY-SIX (26)

All but thirteen of the fifty states will choose governors today. Currently, Democrats hold the majority of governorships (twenty-six Democrats, twenty-three Republicans, one independent). The Republicans are likely to win a majority of governorships and that is a symbolic success.

But twenty-six is just a measuring point. Look at where Democrats and Republicans win. If Democrats secure the governorships of the nation’s most populous states—California and New York—as seems likely, that’s a significant bright spot for the party. If they hold the governorships of Illinois, Maryland, Massachusetts and Ohio, and pick up governorships in Minnesota and Vermont—all possible—that’s even better news. If they take Texas, as Jim Hightower and other analysts say could happen, there is reason to celebrate.

Governors have immense power, not just when it comes to the administration of their states but in the redistricting process that will draw Congressional district lines and in the 2012 presidential race. The right pattern of Democratic wins could be the best news of the night for Obama.

THREE THOUSAND SIXTY-THREE (3063)

Democrats currently control a solid majority of the nation’s state legislative seats, as well as most legislative chambers. That gives the party a great deal of power, especially when it comes to redistricting.

The real question with regard to redistricting is this: How many states will one party control both legislative chambers? Currently, Democrats control both chambers in twenty-seven states, while Republicans control both chambers in fourteen. Another eight states have divided legislatures, with one chamber controlled by each party. (Nebraska has only one chamber and it is elected on a nonpartisan basis, although Republican-friendly legislators traditionally dominate it.) Republicans anticipate major gains in this year’s legislative contests, and hope to gain control of as many as a dozen addition legislative chambers.

GOP strategists suggest that big gubernatorial and legislative pickups could position the party to use the redistricting process to draw another twenty-five Republican-leaning Congressional districts. That could spell big trouble for Democrats in 2012.

It will take a day or so to shake out all the wins and losses, and many chambers could be narrowly divided between the parties. But one good measure of where things are headed is the breakdown of legislative seats won or lost. If Republicans win a solid majority of the overall number of seats in play, that bodes well for them. If Democrats keep things close to even, that could make the redistricting process a more balanced affair.

The majority figure for seats in play this year is 3,063. If Republicans get above that number early, strap yourself in—it could get a little rough.