The real negotiations to reach a budget deal occur in unscheduled visits and late-night phone calls between two men you’ve probably never heard of.

At one end of the Capitol is Barry Jackson: quiet and unflappable, a plump, shaggy and rumpled Midwesterner who loves auto racing (he’s a regular at the Indy 500) and settled in Washington 20 years ago as John Boehner’s right-hand man.

At the other end is David Krone: hard-nosed and crafty, a multi­millionaire former cable lobbyist who travels around playing the best golf courses, prefers fine shirts and custom-tailored suits, usually pinstriped (“Definitely not Jos. A. Bank,” says an associate), and looks up to his boss, Harry Reid, the way a son idolizes his father.

In this budget showdown, they are the negotiators. And they share a few similarities. Their birthdays are in October, 12 days and six years apart. Both men are laconic and fiercely loyal. They rely on their encyclopedic memories — Krone, for example, can effortlessly repeat dialogue from the HBO series “Entourage” — in ever-complicated budget talks.

While both men are seasoned political operators, they are not appropriators. Neither has much direct experience in shaping congressional budgets — and unlike aides who have worked on the budget for years, Jackson and
Krone may not know all the inside tricks. That is said to have caused occasional tensions with staffers who are expert in fiscal policy.

When the House speaker and Senate majority leader met with President Obama late Wednesday night in the Oval Office, Obama was backed by a handful of administration officials. But Boehner had only Jackson at his side; Reid, only Krone.

After their bosses went home, the two chiefs of staff stayed at the White House working into the night toward a compromise. They talked again the next morning.

“He’s got such a good relationship with Boehner, he knows how much leash he has, and he uses it all but doesn’t go over,” Republican strategist Karl Rove said of Jackson, a longtime friend and former colleague. “He understands where Boehner’s red lines and limits are.”

The same is said of Krone.

“He’s got the full confidence of Leader Reid in representing his position,” said Susan McCue, Reid’s former chief of staff and political alter ego. “There isn’t a lot of fog on where he stands. He’s quiet, but he doesn’t dance around the hard facts and truths at hand.”

While their principals fire rhetorical salvos, sometimes by the hour, Jackson and Krone have kept their channel clear of fiery politics. They’ve been negotiating for weeks, usually multiple times a day, in a tone associates described as respectful.

Sometimes, including for several hours Thursday afternoon, Jackson and Krone are joined by two senior administration officials, Office of Management and Budget Director Jacob J. Lew and White House Office of Legislative Affairs Director Rob Nabors.

Most of their work takes place in short phone calls. The other night, Krone was talking with an old friend when he got another call. “Barry’s calling,” Krone told his friend. “I’ve got to go.”

Even when they have found common ground, Jackson and Krone have not made final agreements. “Nothing will be settled until everything is settled,” Boehner spokesman Michael Steel said.

For Krone, the budget showdown is a sort of initiation. He became Reid’s top aide in November and has worked in Congress just a year or so. Before that, Krone was an active Democratic fundraiser and telecommunications lobbyist.

Jackson, meanwhile, has been in government since 1991, when he followed Boehner to Washington for his first term. During the 1995 government shutdown, Boehner was the Republican Conference chairman and Jackson was his chief of staff.

Jackson left to be Rove’s deputy in the Bush White House, serving as what Rove described as “the utility infielder,” before returning to Boehner’s staff last year.

Both negotiators are tuned to the politics, and both are grounded in what would be acceptable to rank-and-file lawmakers in their bosses’ respective caucuses.

“Barry just knows,” said Jackson confidant David Winston, a Republican pollster who advises Boehner. “He spends a lot of time understanding where individual members are and what they’re thinking. That’s just hard work. . . . The speaker isn’t just representing the speaker. He’s representing the House. And Barry knows it’s very important to make sure everybody feels that they’re heard.”

Jackson, 50, is the quiet force who managed Boehner’s first campaign and shepherded him through his rise to leadership in the 1990s. After Boehner lost that leadership post, it was Jackson who helped resurrect his career and guide him to the speakership.

Jackson, who is single, lives on Capitol Hill and is a gourmet cook. He has small dinner parties at his home, once cooking up an Italian veal dish that Rove called “unbelievable.”

He shuns the spotlight, but friends cautioned that his soft-spokenness should not be misinterpreted.

“His intensity is inversely proportional to his volume,” said Republican strategist Chad Kolton, a former colleague.

Like Rove, Jackson can be as relentless in his preparation as he is ruthless in his execution, associates said.

“Barry thinks in three dimensions,” Kolton said. “He’s always working on multiple means by which to achieve his objective.”

Krone, 44, is equally strategic, friends said, having spent a career navigating industries and coalition politics. He first met Reid in 1992 when he was working in Colorado and was sent to pick the senator up at the Denver airport. They went to dinner that night and became fast friends, bonding over having both lost their fathers at a young age.

“David does not think of Harry Reid as his boss,” said one of Krone’s closest friends, Fred Davis, a Republican media strategist. “Nor as the majority leader. He absolutely idolizes the man in the way a son looks far, far up to his father. And he has for a long time.”

Krone earned more than $6 million in deferred compensation in 2008 and 2009 from Comcast and the National Cable and Telecommunications Association, according to public records. He was a major contributor to Reid’s campaigns, and Reid brought him onto his staff in 2010 at the onset of a tough reelection battle.

Like his boss, Krone is not especially social in Washington. For years, he went to sleep early and woke up early to swim before work. These days, he is dating Alyssa Mastromonaco, Obama’s deputy chief of staff.

Krone recently bought a home in Georgetown that a friend remarked actually had a garage. The only flaw: Krone’s Porsche Cayenne did not fit inside. So he traded it for a smaller car.

“The trick to David is multifold,” Davis said. “He doesn’t need the money. So he does one of the hardest jobs in government for fun and for the challenge.”