STUTTGART, Germany — At the midpoint of Friday’s men’s all-around final at the gymnastics world championships, six-time U.S. champion Sam Mikulak seized the lead, having dazzled judges with technically difficult parallel- and high-bar routines that oozed fluidity and style.

Then came the pommel horse and a handstand attempt that sent him flying off the apparatus and out of medal contention.

In a narrative that has become all too familiar on gymnastics’ global stage, the American men couldn’t touch the performances of their counterparts from Russia and China in the all-around competition. Russia’s Nikita Nagornyy and Artur Dalaloyan claimed gold and silver, respectively, while China’s two entrants finished fourth and fifth in the 24-man field.

Mikulak, 26, a California native who won eight NCAA titles at Michigan, finished seventh — more than a full point out of bronze, which was claimed by Ukraine’s Oleg Verniaiev. Fellow American Yul Moldauer, a 23-year-old who competed at gymnastics powerhouse Oklahoma, was 16th. In both cases, it represented a step backward from their placements at last year’s championships in Doha, where Mikulak was fifth and Moldauer 12th.

With the 2020 Tokyo Olympics roughly nine months away, the gap between the U.S. men’s gymnasts and the sport’s standard-bearers appears to be growing rather than narrowing.

That’s hardly what the Americans had hoped, but it is the hard truth as countries they would love to supplant keep raising the sport’s difficulty. And it stands in sharp contrast to the U.S. women, who dominate the globe, led by five-time world all-around champion Simone Biles.

The performance deficit of U.S. men’s gymnastics relative to the current world powers has several root factors, few of which can be remedied in the months remaining before Tokyo’s Opening Ceremonies.

The gap has been years in the making — both between the U.S. men and the U.S. women and between the U.S. men and Russian and Chinese men, in particular.

Since 2003, the U.S. women have won 19 medals in the world all-around competition: 10 golds (five claimed by Biles), six silvers and three bronze.

In the same time frame, American men have won two world all-around medals: Paul Hamm’s gold in 2003 and Jonathan Horton’s bronze in 2010.

Three-time Olympic medalist Fabian Hambuchen of Germany, 31, who’s still regarded as a maestro on the horizontal bar despite retiring after the 2016 Rio Games, notes that the chief gap between the U.S. men and the world’s gymnastics powers is the difficulty of their skills.

Gymnastics scores reflect two components: one for difficulty (the D score) and another for execution (the E score). The strategy for tallying the highest score typically boils down to a question of risk vs. reward. A more difficult routine earns a higher D score, yet it’s apt to incur deductions on the E score for any aspect of the execution that’s less than perfect.

In Hambuchen’s analysis, the U.S. men traditionally emphasize execution — doing what they do as well as they can — rather than stretch their limits and risk a sloppy performance.

It’s an emphasis Hambuchen appreciates and admires — to a point.

“The U.S. guys, they have a really good execution,” said Hambuchen, who is serving as an analyst for German television. “They have a huge focus on that, especially when they’re still in college. They’re always trying to not do the highest D score they can; they try to be consistent and clean.

“. . . I am completely with the Americans on this point. But still, this is not college. This is world championships, so you need to raise your D score. The other teams are increasing their D score and just getting higher [marks].”

Horton, 33, who retired after the 2012 Olympics, watched Friday’s competition via his home laptop and remarked on the medalists’ staggering level of difficulty and style, which he characterized on social media as “off the charts” and the “most beautifully executed gymnastics of all time.”

Horton credited Japan’s Kohei Uchimura, who counts six world all-around championships among his 21 world medals, along with two Olympic all-around golds, with proving that extremely difficult gymnastics can be done without sacrificing execution.

Among the current crop of Americans, Horton notes, only Mikulak comes close to the skill that the Russians and Chinese are showing in competition. In Friday’s all-around, Mikulak’s parallel bars routine had a D score of 6.400, the same as that of the gold and silver medalists, while his horizontal bar’s D score (6.100) exceeded those of all three medalists.

But Mikulak has struggled — and did again Friday — to stage complete, medal-worthy performances across all six mandatory events in all-around competitions on the world stage.

Against an all-American field at the U.S. championships, it has been a snap. Mikulak has won six of the past seven U.S. all-around titles, which speaks, in a sense, to the drop-off in skill behind him.

U.S. men’s coach Mark Williams acknowledged Friday that Mikulak would benefit from being pushed more by domestic rivals. But there simply isn’t a pool deep enough to do that.

U.S. gymnasts such as Moldauer are plenty talented and capable of performing quality routines. But even if flawless, they can’t score enough to challenge the world’s best because their skills aren’t difficult enough.

Horton views this as “a generational thing” that he hopes and believes can be remedied by the 2024 Olympics, if the promising crop of juniors develops.

Still, U.S. men’s gymnastics faces deep-seated, systemic cultural challenges in closing the gap on Russia and China. It simply isn’t as popular with boys in America as it is in Asia and throughout Europe.

“I did gymnastics 28 years and quickly knew that gymnastics in the United States is not a premier sport,” said Horton, a Houston native. “It is for women but not for men. We don’t get the best athletes; the best athletes in the U.S. go to play football, basketball and baseball.

“But it’s one of the premier sports in China and Japan. In Russia, it’s huge. They have such a higher level of respect for gymnastics, so they’re getting the best athletes they can find.”