Eighteen. It's the number between 17 and 19. It's Peyton Manning's jersey number and the legal voting age in the United States. Joseph Heller originally called his satirical novel "Catch-18," but "Catch-22" is the name that stuck.
Tiger Woods knows its significance for golf. The 14-time major champion needs four more of those titles to equal Jack Nicklaus' record.
The golf world revolves around this number. It came up on Saturday night after Tiger shot a 79 to miss the secondary cut in the Farmers Insurance Open at Torrey Pines. It's come up practically every day since the last time Tiger won a major at the 2008 U.S. Open.
When people ask, "Is Tiger back?" as they often do, what they are really making a reference to is that meddlesome little number. Could a rocky personal life, injuries or swing changes stop him from getting to 18?
Hearing the number so often should make you want to use it the next time you play the lottery in your local convenience store.
Hank Aaron lived with the specter of 714 for years until he finally broke Babe Ruth's career home run record in 1974. Before we knew about his predilection for other numbers, Pete Rose had an attachment to 4,191. Roger Maris made a career out of 61. Joe DiMaggio's enduring legacy is owed to his 56-game hitting streak. And Ted Williams' phenomenal hitting prowess can be summed up with his .406 batting average in 1941.
On Broadway someday, someone will write a musical told in statistics supplied by the Elias Sports Bureau.
Tiger lives by numbers. Knowing his yardages precisely is a hallmark of his incredible course management. His official website is full of numbers, breaking down every facet of his 79 PGA Tour wins.
But 18 and 19 are the numbers that matter most to him. Sure, he's not the first athlete to live with the pressure of chasing a monumental record. But no one in golf has ever walked Tiger's plank for so long.
Nicklaus didn't begin his pro career, as Tiger did, focused primarily on winning majors and breaking records. And few athletes in any sport have had to deal with Tiger's level of pressure as the main act.
Consider that when Aaron was chasing Ruth's home run record in the early 1970s, he had to face one pitcher at a time, and each game he played in one ballpark among many around the country that were hosting games at the same time.
He knew how guys pitched him. When Aaron did hit his record 715th home run, it was a high fastball off the Los Angeles Dodgers' Al Downing.
Aaron, who received death threats and racist letters during his pursuit of one of sport's most cherished milestones, also had the support of his Atlanta Braves teammates.
So even if everyone didn't fully embrace his assault on Ruth's record, the game afforded him a simple clarity on his way to baseball immortality: one pitcher, one at-bat at a time and a supporting cast in the dugout.
The slugger had power in numbers -- a control of variables that Tiger doesn't possess. Aaron had the long baseball season and hundreds of at-bats per year to reach the magical number of 715.
Tiger has four chances per year to win a major and a very talented and deep pool of players who want to make it very difficult for him to break Nicklaus' record.
Jordan Spieth, Sergio Garcia, Henrik Stenson, Adam Scott and Phil Mickelson, among others, don't want to be obstacles to history, but they are trying to reach their own career benchmarks. Their numbers might not be as ambitious as Tiger's, but they have their own goals. Tiger can't play defense against them, so all he can do is try to beat them with the lowest 72-hole score.
Now 38 years old and in his 18th year as a professional, Tiger concedes that it's much more difficult to win now than it was for him a decade ago.
"I think it's deeper now than it ever has been," Woods said in December. "There is more young talent. There are more guys winning golf tournaments for the first time."
Those of us who have watched Tiger through the years understand the importance of the majors to him, and how the game succeeds as a whole when he wins one of these four events. His success has been the single most important factor in the international growth of the game. And of his 79 career wins, the majors are the most indelible in our minds.
In 2014, Tiger will try to inch closer to that seemingly elusive number of 18 major titles. His embarrassing showing at Torrey Pines is no indication of a downward trajectory in his game. He will almost certainly win a handful of events over the next 11 months.
Yet his sloppy performance at a venue where he has won eight times as a professional is just more proof of the uncertainty of his chances at tying Nicklaus' record or surpassing it.
There is no cap on Tiger's remaining years at the top of the game. On the tour, there are few players in better shape than him, but the pressure to yield major wins could eventually wear him down.
Eighteen. Even if Tiger doesn't reach it, the number will always be linked to his name and legacy. But for now, we watch and wait to see if he can get to 15, 16, 17, 18 and beyond. It's the story of 2014 and every year ahead as long as he plays major championship golf.