The United States has won 15 of the 16 Olympic 4x100m medley finals held since the event was introduced at the Rome 1960 Games. The one that got away is down to President Carter and the 1980 US-led boycott in protest at the Russian invasion of Afghanistan.

Australia claimed Moscow 1980 gold but the USA men remain unbeaten in Olympic waters. Their 27 world records since 1960 include a bull run of the past 52 years and 9 months as standard bearers of pioneering speed as we head into the Paris Olympics. The current one:

WR: 3:26.78 - Ryan Murphy (52.31) Michael Andrew (58.49) Caeleb Dressel (49.03) Zach Apple (46.95) Tokyo 2020ne

Nine days of action get underway at the Paris La Défense Arena on July 27 and if you had to name one quartet for the win in world-record time, the USA would have the edge. Fuel in their tank is supercharged by one of the most impressive - if not the most impressive (if only swimming were bigger, at home and abroad) - unbroken victory runs in world sport.

Tokyo delivered the shocker of the first USA men's 4x200m free quartet to miss the medals altogether. The Stars and Stripes won't want that happening in the medley relay, nor is it likely, though pressure from the growth of teams capable of making the podium continues to build. Is there an opponent ready to break the dam?

In recent years, there have been some distinct cracks in the the American wall, though only at World-Championship level, Great Britain in 2019 and Italy, matching Britain's European record in 2022.

In 2019, Duncan Scott inflicted two wounds in one magnificent swim, his thunderous 46.14 sprint to historic gold for the Brits the fastest 100m free split ever swum. Swum is used deliberately: in shiny suit, Jason Lezak delivered 2008 Olympic 4x100m free gold for the USA in 46.06 chasing down France's Alain Bernard in a boiling, thrilling battle with a dual-duel mission, victory for the USA and keeping alive Michael Phelps' pathway to a record eight golds.

In Gwangju, Luke Greenbank, Adam Peaty, James Guy and Scott pipped the USA by 0.35sec in a European record of 3:28.10. It was the year Adam Peaty clocked 56.88 to make the 100m breaststroke the most impressive of all 100m global standards on any stroke in terms of the advantage the holder holds over the best of the rest. In that winning medley relay, Peaty clocked 57.20. There was much more speed to come, on that fast relay-start clock in a long cycle and in the response from the USA.

The Covid pandemic caused the postponement of the 2020 Olympic Games. The cycle would be five years an d the impact of that has been felt by some ever since.