Back, and to the left. Back, and to the left.

The footage of Thursday night’s fan interference at Fenway Park has taken on Zapruder-like importance in the sporting world.

It’s everywhere. Networks are slowing the tape down frame-by-frame as anchors and talking heads try to determine the motivation of the fan who reached over the right field wall and the justification of Gary Sheffield’s retaliatory shove.

By now, you’ve heard a thousand different interpretations of what transpired, so I’ll keep mine brief.

My own take is that the fan, Chris House, was trying to take a swipe at Sheffield’s cap and, to be cute, was looking away while he did it, kind of like when you tap someone on the shoulder in a joking fashion as you’re walking behind them.

House’s fiancee defended him in one published report, saying he was going for the ball. Well, it was a pretty weak attempt, if you ask me. But then, I’m skeptical that A-Rod actually saved that kid from getting run over on Newbury Street while the Yanks were in Boston. (Mark my words, the hoax will be exposed within a month).

The future Mrs. House and his other defenders have also maintained that House never even touched Sheffield, which of course implies that the BALCO poster boy slipped into an unprovoked bout of roid rage. I’d like to believe this, but then I’d like to believe we’re actually winning the drug war, too. None of us knows the motive except House himself. Really, his motive is meaningless. Whether he actually hit Sheffield is not meaningless in the overall scheme of things, but it is moot when it comes to what really irks me about this whole brouhaha.

I don’t care if the guy lost his contact lenses on the warning track and was waving to a friend to help him find it. Fans have no business stepping onto, leaning into or even sneezing at the field of play. That’s why this House guy was ejected from the stadium, and it should be grounds for the Red Sox to revoke his season tickets.

As for Sheffield, while I can’t blame him for taking a swing/shove back at the fan, he must receive a short suspension, maybe two games. Just as fans can not make contact with players on the field, players can not make contact with fans in the stands, under any circumstances, including self-defense. As the Ron Artest rumble in Detroit demonstrated, it only escalates things and puts more people in danger. If a fan comes on the field/court, that’s something else, but regardless of how threatened they feel, players can’t cross that line into the stands.

Which brings me to the reason why 99.5 percent of these fans are interfering in the first place.

They want a ball.

Forget that someone might get hurt. Forget that they might touch off a brawl. Forget that they might force the umpires to rule fan interference and cost the home team a run or two. None of that matters.

They must have that ball.

At best, they want a ball so they can give it to their young son or daughter. Fans, usually fathers, are willing to run over the 60-year-old grandmother seated next to them to get a ball. God forbid they go home without a ball for little Jimmy or Jane. And, hey kids, look, Daddy’s willing to get thrown out of the stadium so you have something to take to show-and-tell on Monday.

Then there’s the single, overweight, beer cup totin’ guy who will dive over a row of 10-year-olds to get a ball because, well, I really haven’t figured out why. If the ball doesn’t roll quite far enough for him to reach it, said lush figures the next best thing is to throw his beer on the nearest player. In Thursday’s incident, this role was played by the guy in the GAP shirt.

Before every game at every ballpark, there’s an announcement warning fans against interfering with the action on the field. Obviously, it’s ignored by virtually all of the people sitting in the front row, because how many times do we see a ball roll around the right-field corner at Fenway just out of reach of hand after hand after hand?

The average fan figures it’s worth the risk to reach over the wall for a souvenir. If you get the ball and security tosses you from the ballpark, hey, at least you’ve got an authentic, Bud Selig autographed game ball, a dull story about how you got it and an excuse to go across the street to the Cask N Flagon and repeat the story ad nauseum.

If you don’t get the ball, you just wait for the next opportunity. No harm done.

So why don’t we eject anybody who reaches over the wall, whether they touch the ball or not? That changes the risk/reward quotient considerably, doesn’t it? My guess is the sea of hands would dwindle to a trickle.

I’ve never understood why people are allowed to even attempt to interfere with a ball in play in baseball. Is it allowed in other sports where fans are so close to the action, like basketball or golf or arena football? Have you ever been to someone’s house and seen an NBA game ball or Vijay Singh’s Titleist displayed on their mantel or in their trophy case?

Of course not. If anyone even tried to swipe one of those balls, they’d immediately be taken for a walk by security.

So why is it allowed at baseball games?

Randy Whitehouse is a staff writer. He may be reached by email at [email protected]