Date and time: Sunday, 26 April from 0900 BST
Coverage: Watch live on BBC One, with a choice of cameras on the red button and the BBC Sport website; Listen on BBC Radio 5 Live
Where have all the good male British marathon runners gone?
Forget the very top of the elite end for the moment. The problems start just below that level.
Over a period of time, we've lost that depth in quality that was there 20 years ago, and that in turn has had a knock-on impact on British performances at the very top.
We used to have guys like Charlie Spedding and Steve Jones, great club runners who stepped up to record very fast marathon times but were not good enough to win international track or cross country medals.
Not any more. What we're missing is the good club runner who is ready to target the marathon and put in the hours and training needed to make an impact.
Brendan Foster and I were talking about this recently. In 1985, the journalist and then-MP Matthew Parris ran just shy of two hours 33 minutes to finish 385th out of the 20,000 runners.
Had he run that time last year, he'd have finished 83rd out of 34,000; the year before, 46th.
Steve Jones wins in 1985 - in a time not bettered since by a Briton
What this illustrates is the decline in the number of British men who are clocking times between 2 hours 20 minutes up to 2 hours 50 minutes.
It's hard to blame the runners.
There are very few rewards, very few stepping-stones, for those looking to step up.
You're looking at running a minimum of 120 miles a week, sacrificing everything else in your life, and for what? There's no funding available, no altitude training, no help with physio treatment.
The rewards aren't even in the form of money. You want to be competitive, to be figuring in the finishes - but if you do get your time down to say, 2 hours 08 minutes, that still might not be enough to get you in the top 10 at a big race, where the big prizes are.
If you're going to be putting in those hours and efforts, you need to see results to get enjoyment out of it. There's very little intrinsic enjoyment in training your nuts off to finish 21st.
You could argue that there might be the rewards of a trip to the Olympics, but that's not guaranteed - marathon runners know more than most about injury.
Then there's the struggle to get an invite to the big city marathons. As a Briton you'd get on the start line for London, but there's no guarantee you would anywhere else.
British males are still physically capable of it. That hasn't suddenly changed. It's whether they want to do it with those lack of incentives.
Dan Robinson - who finished 13th in London last year in a time of 2 hours 13 minutes 10 seconds - is great because he's prepared to do itl, but there aren't many like him.
Underlying it all is the dearth of good 5,000m and 10,000m male runners we have.
That's where marathon runners will come from - guys who can run good times on the track at those distances and then move up to the longer distance.
Mo Farah's ability over 5km and 10km will help, but until we have 10 guys who can run between 27 mins 30 seconds and 28 minutes 30 seconds for 10,000m, nothing much will be done.
What can be?
We can start by giving people incentives with the right kind of support - funding, altitude training camps, physio.
We then need to set up the right competitive opportunities, just as the British Milers' Club has for the mile.
At BMC meets you have pace-making, and you also have as many as six graded races, so there are targets to aim for and races to win no matter what your standard.
Dan Robinson came close to a PB at the Olympics
We've got the 10,000m back at the national trials, which will help, but we need more. There's no point in getting invites to places like Brussels - we need races that our guys can be competitive in.
If we can get one or two to break through - like with Tom Lancashire and Nick McCormack going under 13 minutes 30 seconds for 5,000m - then it will drag others upwards. If you're battling with someone else, your standards will rise.
At a deeper level, we need to make athletics more attractive to more people.
Running is incredibly popular, but only in certain sectors of society, at certain distances and in the mass-participation, non-competitive races.
There are loads of kids lining up to take part in the junior Great North Run, but we need to make the rest of the sport interesting for them.
I watch my 16-year-old son compete, and the current set-up just isn't exciting enough for kids to want to stay involved and do the training.
It isn't just a numbers game, but the more kids we get running, the better chance we have of producing another great British distance runner.
Steve Cram was talking to BBC Sport's Tom Fordyce