For conspiracy theorists, it seems only two events really matter. One, of course, is the Kennedy assassination. The other is the NBA playoffs.

Every year, a controversial call of some kind inevitably results in a losing team feeling robbed. Okay, so far so good — this is no different from football or baseball or countless other sports.

Where the NBA is unique, however, is in the persistence of fans insisting there was some kind of ulterior motive behind the officials’ decisions. It needn’t matter how laughable the premise; you can guarantee somebody will come up with a reason why the league wanted the Spurs to beat the Suns, or Miami to beat Dallas in the Finals a year ago, or countless other outcomes. The players aren’t immune from this either — witness Heat players calling a certain referee “Knick Bavetta” after a close playoff loss several years ago.

The latest entry in the conspiracy file came in the fourth quarter of Monday’s Game 4 between Utah and San Antonio. A closely contested game blew open when the Spurs enjoyed a 25–2 free throw disparity in the fourth quarter, helping them wrap up a 91–79 victory despite making only four baskets in the period. Official Steve Javie, in particular, seemed to have it in for the Jazz, giving every 50–50 call to the Spurs and handing out four technical fouls against the Utah side in the final stanza.

This immediately had Jazz fans shouting “fix!” — as though the NBA had some kind of vested interest in seeing the vanilla, ratings-killing Spurs advance through another round of the postseason. But the reality is irrelevant — the perception still hurts the league.

That’s why the officiating question is so much more important for the NBA than it is in baseball or football. When a botched call by Bennett Salvatore led to a last-second jump ball and, ultimately, a Lakers victory in Game 4 of their first-round series against Phoenix last year, a number of otherwise intelligent people just presumed that the league had predetermined that L.A. should win this one. Just like they presumed the refs had an agenda four years earlier in Game 6 of the Western Conference finals between L.A. and Sacramento, a game L.A. won thanks to a ludicrous free-throw advantage.

It’s easy to see why the league might want to favor teams from big markets like L.A. or Chicago — the two most common targets in recent yore, given their nine championships since 1990. Conspiracy theorists have had a bit harder time with the Spurs of the world, however. But with San Antonio poised to win its fourth title in eight years, that hasn’t stopped them from trying.

They’ve had some ammo of late. First there was the Spurs-Suns series in the conference semifinals. Depending on whose side of the story you hear, the Suns were either deprived of a championship by a one-sided ruling by the league office, or shot themselves in the foot by violating a rule everybody has known about for years. Either way, center Amare Stoudemire and forward Boris Diaw were suspended for Game 5 after they left the bench area during an incident at the end of Game 4 — an incident San Antonio started. As a result Phoenix lost Game 5 and, ultimately, the series.

And we’ve had two more controversial games in the conference finals — in addition to Monday night’s Spurs-Jazz tussle, there was a highly questionable no-call on LeBron James’s final shot in Game 2 of the Eastern Conference finals. Detroit’s Richard Hamilton appeared to foul him on multiple occasions during his foray to the rim, but no whistle blew, and the Pistons ended up winning by three.

Coming on the heels of last year’s postseason — where the conclusion of Game 5 of the Finals had Dallas fans searching for a second Zapruder film — the NBA obviously is anxious to avoid an encore performance. Yet in today’s era of instant message board analysis and YouTube medleys of bad calls against a team, it seems almost inevitable.

Some of the damage has been self-inflicted. For instance, Stu Jackson’s rulings on disciplinary matters have appeared to have no rhyme or reason — something that won’t surprise those who saw him coach the Knicks or run the expansion Grizzlies — and the Stoudemire/Diaw judgment was the latest example.

Yet much of it comes down to the fact that the average Joe thinks he can officiate an NBA game just as well as the zebras. This isn’t the case with other sports. In baseball or tennis, the only judgments are about position and timing, and replays almost instantaneously show the officials were right the vast majority of the time. Football has the opposite advantage — the rules are so obscure that the only thing fans really get up in arms about are offsides and pass interference, because those are the only things they understand.

But in basketball, officiating is as much art as science. Even a slowmotion replay often fails to determine conclusively whether a player was fouled or not, especially in the modern era where players have turned flopping into an art form. The result is that everyone has an opinion. Fans of either side will almost always have a call or two — or 20 — they can complain about when the game ends, and insist that was the reason their team lost.

Since it happens so often it’s only natural for some to wonder if a higher power, such as the commissioner’s office, is involved. This is batty, of course — consider the logistics, people — but it’s proven amazingly persistent.

A second look at the 2006 Finals is instructive. When the Mavs lost Game 5, Dallas owner Mark Cuban allegedly yelled at David Stern that the league was fixed (though he has denied this), and an armada of Dallas fans voiced the same sentiment. Contrast that to the 2006 Super Bowl. The Seahawks lost with the help of several controversial calls, yet nobody even considered taking it a step farther than that. It was just bad officiating, in the eyes of everyone — not some clandestine effort by the league to disenfranchise the Seahawks.

It may not be fair, but the public views the NBA much differently. And until that changes, the league has an obligation to minimize the officiating questions that have dogged it in the past two postseasons. On this, I’m not sure they’re doing as well as they could be, with the Utah-San Antonio Game 4 providing the latest example. They need to do better, because they’re giving the conspiracy loonies a trove of new material every spring.

jhollinger@nysun.com