Last November, word emerged from the FINA technical swimming committee that the introduction of mixed relays into international competition was being considered. At his stage it’s still a vague proposal and it’s not clear how or when they might be introduced into the world championship programme, but there is precedent in that the Youth Olympic games featured both mixed 400m freestyle and medley relays. Equally the mixed freestyle relay was famously swum in the 2007 duel in the pool, when Libby Lenton’s lead off time of 52.99 was disallowed as a world record due the potential draft she received from Michael Phelps in the adjacent lane.

While there’s no immediate prospect of the event taking place, purely in interest, we looked at how Britain would make up relay quartets should the event have been included in Shanghai last year, using 2011’s rankings as a guide and a 0.5 second tolerance per takeover.

For the freestyle relay selection is straightforward; pick the two fastest men and women from the rankings and line them up at the start line. That gives the following team:

GB Freestyle
Name	Time
Adam Brown	00:48.84
Simon Burnett	00:49.09
Fran Halsall	00:53.48
Amy Smith	00:54.93
Total Time	03:26.34
Takeover Tolerance	00:01.50
Final Time	03:24.84

Out of interest, Australia’s time at the 2007 duel was 3:23.41, much faster, but the USA could only manage 03:25.80. The prospect of GB beating the USA in reality seems remote however.

Picking a medley relay squad is not so straightforward due the required stroke combinations, but the fastest team is obtained by picking the two top ranked ladies who are closest to their male counterpart. Consequently there’s no place for Lizzie Simmonds or Stacey Tadd, while Anthony James and Adam Brown make way on the fly and freestyle legs.

GB medley	Men		Women		Difference
100 backstroke	Liam Tancock	00:53.25	Elizabeth Simmonds	00:59.80	00:06.55
100 breaststroke	Michael Jamieson	01:00.79	Stacey Tadd	01:09.08	00:08.29
100 butterfly	Antony James	00:52.13	Jemma Lowe	00:57.43	00:05.30
100 freestyle	Adam Brown	00:48.84	Fran Halsall	00:53.48	00:04.64
	Total Time	03:44.95
	Takeover Tolerance	00:01.50
	Final Time	03:43.45

The medley relay wasn’t swum at the duel, hence there’s nothing in the senior record books to compare against, so for context we looked at how the USA and Australia might fare under the same circumstances. Interestingly none of the three teams has the same combination of men and women, which is largely a function of the excellence of Rebecca Soni and Michael Phelps. Alicia Coutts was the top ranked Australian in both butterfly and freestyle, but can clearly only swim one leg; in this instance her freestyle wasn’t quite quick enough to make the grade.

USA medley	Men		Women		Difference
100 backstroke	Nick Thoman	00:53.01	Natalie Coughlin	00:59.12	00:06.11
100 breaststroke	Brendan Hansen	01:00.08	Rebecca Soni	01:04.91	00:04.83
100 butterfly	Michael Phelps	00:50.71	Dana Vollmer	00:56.47	00:05.76
100 freestyle	Nathan Adrian	00:48.05	Missy Franklin	00:53.63	00:05.58
	Total Time	03:42.26
	Takeover Tolerance	00:01.50
	Final Time	03:40.76
Australia medley	Men		Women		Difference
100 backstroke	Haydn Stoeckel	00:53.70	Emily Seebohm	00:59.21	00:05.51
100 breaststroke	Brenton Rickard	01:00.04	Leisel Jones	01:06.18	00:06.14
100 butterfly	Geoff Huegill	00:51.83	Alicia Coutts	00:56.94	00:05.11
100 freestyle	James Magnussen	00:47.49	Alicia Coutts	00:53.78	00:06.29
	Total Time	03:43.68
	Takeover Tolerance	00:01.50
	Final Time	03:42.18

All of this is of course intensely theoretical, and in any case takes out any concept of tactics. In the medley relay for example, the USA would be way ahead of the rest, but at the 300m stage GB would be 4.72 seconds ahead of Australia, having swum two men already to Australia’s one. That would leave consummate anchor leg swimmer Fran Halsall battling to hold off a fast finshing James Magnussen. No doubt Halsall would relish being the hare in that match up. Maybe it’s one we might see in the future.