B-Hop better stop.

The time comes for every fighter when continuing is a case of diminishing returns. Forty-three year old Bernard Hopkins seemed to hear that whispered message last Saturday night as he nearly tricked and slicked his way to a victory over undefeated super middleweight champion Joe Calzaghe in Las Vegas.

In the end, Hopkins’ hand was not raised. He lost a split decision just closely enough to be questionable in the opinion of his supporters but not controversial in the minds of anyone save, perhaps, Hopkins himself.

“I don’t think he won, so how can I give him credit?’’ Hopkins said ungraciously after two judges had Calzaghe winning by three and a hard-to-fathom five points while the third, Adelaide Byrd, gave Hopkins a career achievement award with a 114-113 margin of victory.

“I got beat tonight but not by Joe Calzaghe. I took the guy to school. I made him look amateurish. Joe throws punches like my sister. To give him credit now would be submitting to the situation and I refuse to do that.’’

Hopkins was partially correct. The passage of time and the inexorable physical erosion that comes with it for a boxer had as much to do with Hopkins’ loss as did Calzaghe but the fact is Calzaghe went down in the opening minute of the fight from a straight right hand to the nose and lost the next round as well. So he was three points down in the opinion of most, and already forced into the kind of slower-paced fight Hopkins hoped to create with his biggest fight barely underway; yet he still came back to win.

By the fight’s mid-point, Calzaghe had taken a one point lead on two of the judges’ cards and from the fifth round on Hopkins won only one round on those two cards. The reason was that for the first time in his career Hopkins faded badly over the final few rounds, his legs deserting him perhaps because he had chosen to spend most of the fight retreating in an effort to lure Calzaghe into a mistake of over enthusiasm.

He didn’t make it, but neither did Calzaghe look good in victory. What he looked like was a guy who slaps more than punches and who in this case had problems landing anything clean against a 43-year-old man. Yet that did not mean he wasn’t landing.

According to Compubox’s often suspect “statistics,’’ Calzaghe struck Hopkins 232 times, which were the most ever landed on him in the 21 Hopkins fights tracked by the CompuBox calculators. He also outlanded him by more than 100 punches but more importantly he out-threw him by a margin of 239 (707 to 468). It was expected that Calzaghe would be the busier fighter because Hopkins is a cautious counter puncher by nature while Calzaghe is one of the busiest boxers in the business. What was not expected was that Hopkins’ fight would grind to a halt in the final three or four rounds.

One measure of Hopkins’ successful plan was that it reduced Calzaghe’s punch output to 58.9 per round, well below his normal average in big fights where he is often in excess of 70 punches a round. But while Hopkins succeeded in forcing Calzaghe into fighting his fight he wasn’t able to win it because by the 10th round he was, as they say in Calzaghe’s native Wales, ‘’knackered.’’

When the bell sounded to open Round 10, Hopkins was still on his stool, a telltale sign of a man whose body was arguing with him about what to do next. Less than a minute later, Hopkins was rolling on the floor claiming a low blow. A replay showed Calzaghe had hit him low in part because Hopkins was pulling his neck down, but the punch was also half blocked by Hopkins and so its power was greatly dissipated.

Still, referee Joe Cortez gave Hopkins a full five minute rest period and he needed every minute of it.

The next round he tried the same thing, with Cortez less cooperative this time,  and Calzaghe would later contend had Hopkins’ not been given “rest breaks’’ in a sport that has no timeouts, he would not have gone the distance.

That is debatable, because Calzaghe never seemed to land a clean blow on the shifty Hopkins, but what is not is that Bernard Hopkins has come to that crossroads all fighters face. It is time to stop. Now it is not only outsiders who are telling him that, it’s his body. Whether he listens is up to him, but his long-time co-trainer Nazim Richardson said before the fight and repeated it after that the counsel he’d given Hopkins was to beware the timeline of boxing.

“I told him he’d experienced everything there is in boxing but a bad beating,’’ Richardson said. “No reason he has to. At 43, what else is there for him to do?’’

Nothing now that he’s financially comfortable and established as a fighter of some historic import. To continue is to tempt cruel fate, a fate that is always the same for the fighter who stays too long. It is to end up wearing sunglasses at midnight.

As for Calzaghe, his future at 36 seems equally clear. He said he intends to retire at the end of the year and so will probably fight only once more. He’d love for that opponent to be current middleweight champion Kelly Pavlik, but that is not going to happen. Pavlik’s promoter, Bob Arum, has no interest in such a fight nor does Pavlik need it.

That leaves Calzaghe with no viable opponent at 168 pounds if he chose to retain his super middleweight titles and no reason to fight the American young gun at light heavyweight, Chad Dawson, because Dawson is too much risk for not enough reward either financially or in the court of public opinion.

What that means is a fight against another faded legend in 39-year-old Roy Jones, Jr. or the blunted force that was once Felix Trinidad. In the end it seems nearly certain the choice will be Jones, who was everywhere in Las Vegas last week saying he’d happily journey to England or Wales to face Calzaghe. In fact, he proposed a two-fight deal which seemed absurd but was an indication of how anxious another old man is to get in with Calzaghe before he too retires.

“I’d love to go to Wales and fight in front of 70,000 or 90,000,’’ Jones said. “I’d like to propose a two-fight deal. The first one ever there. If there’s a reason to have a second one, we fight it over here.’’

This from a guy who in his prime refused all efforts to get him to leave the U.S. to fight in England or Germany, turning down offers to face Calzaghe and the then undefeated German WBO champion Dariusz Michalzewski in his (and their) prime.

“When I was on top of the world, why would I go to the other guy’s place?’’ Jones asked. “If he’s going to beat me and I’m the best in the world come to my place.’’

Jones spoke first of a 60-40 split to his advantage but quickly amended it to 50-50, the same tactic Hopkins used before he signed to face Calzaghe. That seems likely to be what the terms will be if the fight is to come off but it is a long road between talking with Roy Jones, Jr. and getting him to sign a contract. In the end however it seems all but guaranteed.

As for Bernard Hopkins, he’s fighting himself now and that is how it should be. He’s fighting to do what boxing is telling him to do, which is box no more.

“I haven’t had time to smell the roses yet,’’ Hopkins said at a post-fight press conference that was at times contentious and at other times more like a valedictory address for a man on his way out. “Maybe this is the time for me to stop and smell the roses.’’

That would be wise, because to make another choice is to all but guarantee a time is coming to taste his own blood and perhaps write an ending to his career in boxing no different than that of all the fighters Nazim Richardson was gently warning him about.