September’s mortifying Mets collapse prompted me to finally update my “Levels of Losing” column from 2002, which was culled from years and years of unfortunate experiences as a sports fan. Please note that we’re ignoring run-of-the-mill losses and concentrating on memorable defeats (buzzer-beaters, blowouts, choke jobs, etc.) in big moments (pivotal games in a playoff series, Game 7s, NFL playoff games, losses that submarine regular seasons, etc.).

Back in 2002, we only had 13 levels. Now? Sixteen. The list keeps growing. Here are those 16 levels in order of least painful to most painful.

Level XVI: The Princeton Principle

Definition: When a Cinderella team hangs tough against a heavy favorite, but the favorite somehow prevails in the end (like Princeton almost toppling Georgetown in the ’89 NCAAs). … This one stings because you had low expectations, but those gritty underdogs raised your hopes. … Also works for boxing, especially in situations like Balboa-Creed I (“He doesn’t know it’s a damn show! He thinks it’s a damn fight!”). … The moment that always sucks you in: in college hoops, when they show shots of the bench scrubs leaping up and down and hugging each other during the “These guys won’t go away!” portion of the game, before the collapse at the end.

Personal Memory: The first round of the ’95 NBA playoffs between Boston (No. 8 seed) and Orlando (No. 1 seed), the final season of the Boston Garden, when the C’s (with a motley group of has-beens and nobodies) split the first two games in Orlando, then nearly polished off the Magic at home before Shaq, Penny and the gang prevailed. Those Celtics were woefully overmatched, but it was the magical Garden’s last gasp; the electric atmosphere suckered us into thinking, “Damn, we might actually win this thing!” It was extremely tough to leave that place after Game 4.

Level XV: The Achilles’ Heel

Definition: This defeat transcends the actual game, because it revealed something larger about your team, a fatal flaw exposed for everyone to see. … Flare guns are fired, red flags are raised, doubt seeps into your team. … Usually the beginning of the end. (You don’t fully comprehend this until you’re reflecting back on it.)

Personal Memory: During the first quarter of the Chargers-Pats blowout, the broadcast either split-screened Bill Belichick and Norv Turner or showed them consecutively — poor Norv was vacantly staring out to the field, like he couldn’t remember if he’d left the lights on in his rental car or something — and I remember thinking, “Holy crap, their head coach is Norv Turner! We can basically cross the Chargers off the list of 2007 AFC contenders; it’s down to the Pats, Colts and Steelers!”

Best Example: We just had two in the first month of the 2007 NFL season — San Diego getting crushed by New England (the day everyone realized that Norv Turner and Ted Cottrell were prominently involved in the 2007 Chargers season), and Dallas crushing the Rex Grossman era in Chicago and causing Bears fans to start chanting “Griese! Griese!” (Like Brian Griese could ever save the day.)

Level XIV: The Alpha Dog

Definition: It might have been a devastating loss, but at least you could take solace that a superior player made the difference in the end. … Unfortunately, he wasn’t playing for your team. … You feel more helpless here than anything. … For further reference, see any of MJ’s games in the NBA Finals against Utah (’97 and ’98).

Personal Memory: Flipping things around, remember Game 5 of the ’99 ALDS (Red Sox-Indians), when Pedro Martinez came out of the bullpen and slammed the door on Cleveland’s season? Six innings of no-hit ball with an injured shoulder? Nothing you could do about that. Pedro came jogging in from the bullpen like Clint Eastwood … and Indians fans knew they were finished. See you next year.

Level XIII: The Rabbit’s Foot

Definition: Now we’re starting to get into “Outright Painful” territory. … This applies to those frustrating games and/or series in which every single break seemingly goes against your team. … Unbelievably frustrating. … You know that sinking, “Oh, God, I’ve been here before” feeling when something unfortunate happens, when your guard immediately goes shooting up? … Yeah, I’m wincing just writing about it.

Personal Memory: The Red Sox-Yanks playoff series from ’99, when everything went against the Sox — two potential homers bouncing off the top of the wall, egregiously bad umpiring, seeing-eye singles and bloop hits and everything else. After a while, you start battling that nagging, unshakable, “It’s not our year” feeling, which takes on a life of its own and swallows your team whole. Nothing destroys a season faster than bad karma.

Level XII: The Sudden Death

Definition: Is there another fan experience quite like overtime hockey, when every slap shot, breakaway and centering pass might spell doom, and losing feels 10 times worse than winning feels good (if that makes sense)? … There’s only one mitigating factor: When OT periods start piling up and you lose the capacity to care anymore, invariably you start rooting for the game to just end, just so you don’t suffer a heart attack.

Personal Memory: Game 1, Bruins-Oilers, 1990 Stanley Cup Finals, the tail end of my sophomore year in college, when everyone from school trekked down to Cape Cod for seven days of drinking and general mayhem. On this particular night, my buddy Sully and I skipped out of a party to watch the third period at a Hyannis bar. Just the third period, right? It ended up being the first OT. And the second OT. And the third OT. Imagine the most nerve-wracking moment of your life, then imagine it ballooning to three-plus hours. That’s playoff hockey.

Anyway, by the time Edmonton’s Petr Klima drove a stake into our hearts around 1 a.m., we were drunk, drained, jittery and semi-suicidal. I don’t even really remember what happened after that. I think we ended up walking down Route 6 and hitchhiking or something. Who knows? We didn’t even know what to do. If I bumped into Sully 50 years from now, “Glen Wesley missing the net in the second OT” would be the first thing we brought up. I can’t even talk about this anymore.

Level XI: Dead Man Walking

Definition: Applies to any playoff series in which your team remains “alive,” but they just suffered a loss so catastrophic and so harrowing that there’s no possible way they can bounce back. … Especially disheartening because you wave the white flag mentally, but there’s a tiny part of you still holding out hope for a miraculous momentum change. … So you’ve given up, but you’re still getting hurt, if that makes sense. … Just for the record, the 2002 Nets and 2005 Astros proved that you can fight off The Dead Man Walking Game, but it doesn’t happen often.

Decent Example: Remember Game 5 of the Eastern Conference finals in ’93 (Knicks-Bulls), when Charles Smith had all those chances to make the winning layup and kept getting stuffed, so the Knicks lost home-court advantage and had to travel to Chicago for Game 6? They didn’t have a chance in hell. Bring this game up to a Knicks fan and they invariably start dropping f-bombs.

Personal Memory: Two quintessential examples, both from the ’86 baseball playoffs.

• Games 6 and 7 of the 1986 ALCS (Red Sox-Angels), following the dramatic Game 5 when the Angels (three outs from the World Series) blew a 5-2 lead in the ninth inning (capped off by Dave Henderson’s go-ahead homer with two strikes and two outs in the ninth, as policemen surrounded the field and the Angels bench was ready to run out to celebrate). If that wasn’t bad enough, the Angels tied the game in the bottom of the ninth, had two chances with the bases loaded to score the winning run, then blew the game in the 11th. Then they flew cross-country to Boston to play Games 6 and 7, which they promptly lost by a combined score of 132-2. Talk about Dead Man Walking.