St. Louis light heavyweight Ryan Coyne has unfortunately had to learn the hard way what too many fighters have also had to learn in recent years: Don King, once the ruling promoter of the sport of boxing, is now little more than a sideshow, and far from a man with the power of Bob Arum's Top Rank, or the Richard Schaefer and Oscar De La Hoya-led Golden Boy Promotions.

Coyne, now 30, has been promoted by King for a few years, at least in theory. Really, though, he's been forced to promote his own cards most of the time, while King fails to secure fights for him. Other fighters over the last decade or so have experienced these same problems, and most of them have left King at the first chance they got, including Devon Alexander, Cornelius Bundrage, and Juan Diaz, among several others.

Coyne was scheduled to receive his first world title shot late last year, when he was to face Nathan Cleverly on a Golden Boy-promoted show, with the fight airing on Showtime. Instead, King blocked the fight from happening, leading to Coyne being replaced by Shawn Hawk.

Whether or not you think Coyne (21-0, 9 KO) really deserved a world title shot isn't even the point. He was getting an opportunity, and then the man who was supposedly looking out for his career put a stop to it.

Recently, Bernard Hopkins loudly spoke of ending King's career when he beat Tavoris Cloud in March, and Hopkins, a former King fighter himself, who had a very public and nasty split with the promoter, went ahead and beat Cloud. Much of the media, particularly those who don't regularly follow boxing that closely but reported on Hopkins' endless great story, bought into it -- as King's last really notable fighter, Cloud losing his world title and his "0" essentially put King down and likely out.

Of course, Don will be around as long as he wants to be, and he's promoting this Friday night's ShoBox card from the Treasure Island in Vegas. King has spoken glowingly about this venue before, but it's a mark of the entire situation that King has to be so thrilled to have a second-tier (at best) Vegas venue host his "bigger" shows.

In reality, King hasn't promoted a big show in a long time. While Arum has had Manny Pacquiao, and Golden Boy has run with Floyd Mayweather's events, the biggest fights King has been associated with were led by others, with King's fighters usually in more of an "opponent" role. When Arum and King buried the hatchet to promote a 2011 card in Vegas, King served washed-up veteran Ricardo Mayorga to Miguel Cotto for a rehab fight.

Cotto made $1 million on the Nevada commission purse report that night. Mayorga was paid a $50,000 purse, and after fees and debts were taken out, Mayorga's reported takeaway money was less than $15,000. This was a Showtime pay-per-view event. Even if you suspect that Mayorga made more money off the books (again, I've seen reported purses of $1, and I'm not missing any numbers), he wasn't paid much given that he was fighting a top talent, and still had at least a little name value of his own.

The fall of the heavyweights has had a huge impact on King. But more than that, the sport has simply changed, and he hasn't been able to keep up.

Coyne told BoxingScene.com that he doesn't consider King his promoter anymore, and says his act has grown stale. He also feels he's being set up in this fight against Marcus Oliveira (24-0-1, 19 KO), another fighter he says has been "trapped in the Don King dungeon."

"Don King is not my promoter. I'm not really sure who or what he promotes anymore. Last time I was browsing the net I saw him carrying on about the Iron Chef or some other incoherent garbage. He bids on fights, signs contracts, and never follows through on them. His hustle is tired. Professional promotional outfits don't conduct business in that manner. Things can never improve when one party refuses to treat the other like a human being, so of course not. Make no mistake, this fight is a setup. He doesn't want this legal spat anymore than I do. It's pointless with nothing to gain. King wants to see me get beat, but a setup blows up in your face when you send the hitman back to the boss in a duffle bag. I'm well aware of the factors at play here and I'm coming to wreck plans."

King's purse bid defaults are quickly becoming one of boxing's running jokes. His absurd $1.1 million bid on a Chris Arreola-Bermane Stiverne fight shocked the boxing community, at least for a few seconds, before everyone realized he would default on that bid, and that it would fall back to Arreola's promoter, Dan Goossen, who bid a more sensible $550,000.

King called it a "super fight." And then, to the surprise of no one, he failed to put the fight together, and it went to Goossen.

King's last hope for a top fighter is probably Angelo Santana, a 24-year-old lightweight, a Cuban southpaw with power and skills. Santana is in the ShoBox main event on Friday, and he looks like he has a real future. But can a promotional company be built around a Cuban lightweight? Probably not. (Sorry, 50 Cent.) And what's more, if Santana is going to actually become a player in the sport, the reality is that he'll need to get away from King.

King, now little more than an exuberant collector of miniature flags, will never be the promoter he once was. His public persona is now about all he has -- when the cameras are off, he still reeks of the same shady boxing promoter the world grew, for whatever reason, to embrace and love, despite the destruction he has left in his wake. Only now, he's less powerful.

Don King once ruled the sport, and ruled it when it was a far bigger deal than it is today. Now 81 years old, he is a relic. While longtime sworn rival Arum has adapted and changed with the times, King has fallen by the wayside. He is not only lagging behind the big two of Top Rank and Golden Boy, but also Lou DiBella, Gary Shaw, Dan Goossen, and others, as well. And that's just counting American promoters. Globally, King probably isn't in the top 25 of boxing promoters anymore.

Don King will never promote another truly major fight. Occasionally in recent years, someone would remark that King could "save" boxing with one of his glamorous events. His pay-per-view cards from his prime years blow away the undercard fare we are offered now.

Those fans, though, hadn't watched for a while, obviously. King can't even make a fight as big as the first fight on one of his old pay-per-views. He tries desperately to sell his fights as events, speaking of Tavoris Cloud-Gabriel Campillo as if it were more than an undercard bout on Dan Goossen's show. He said the rematch of that bout -- which Cloud, King's fighter, stole via terrible judging -- could be held in a stadium in Florida, Cloud's native state, in front of 100,000 people. It was just talk, and it was just King squawking as he loves to do, but it's become less chuckle-worthy and more sad as time has wore on. King's entire schedule of fights in a calendar year now don't draw nearly 100,000 fans combined.

He'll stick around. He'll pop up for colorful quotes now and then; whether or not they make any real sense is hardly the point at all anymore. He'll wave his little flags, and at times, he will appear as though he's still truly part of the boxing landscape. He'll sometimes promote a boxing card, crowing about the great facilities at an also-ran Vegas casino, or some arena in Florida that he's papered to make it appear that someone actually cared to see the fights.

And now, as he wearily sits upon a ragged throne in the decimated ruins of what once was boxing's biggest empire, it is truly clear that Don King is finished. Only the caricature bordering on self-parody remains.