Jersey_guy,
Good data. And I agree somewhat with what you say (as I will get into below), but just to take one runner you mention; Gert Thys and his 2.06.33.
You say he has never run sub-28/10k, and I believe you. But consider this, Geb can run a 10k , 33 seconds per mile faster than his marathon pace,. You don't think that if he really aimed for it Gert could not run a 10k a mere 19 secs/mile faster than his marathon PR? (and thereby break 28.00?)
I think most people would expect that he COULD do that than would believe that he COULD NOT do that.
I know I'm dragging you into a hypothetical situation here, and I don't like that, but you get my point. No need to agree, or disagree yet. Read on.
Joe Rubio,
Pretty much agree with you too, for the same reason. In fact if you waded thru my many posts on this topic you would have noted that I said that you need not have achieved the 5k/10k times required to pop the marathon time, but that you should be "capable of it" if you're going to pop a world class marathon.
Which is like I explained to Jersey_guy above; I would say that if you can break 2.07, it's pretty much a given that you can go back down, train seriously and run a sub-28.00 time.
Note that I also said you did not have to be able to do both of these concurrently (even within the same year!). In fact I pointed out that if you currently have the speed for 5k/10k there's a good chance you'll have compromised your current marathon potential.
I think in essence what Al Sal is doing is saying to himself, "Before I could run 2.08, I had been able to run XX for 10k, so I need to search for some guys in that kind of shape and move them up."
It's logical, although maybe not the only possibility.
You term this thinking "cart before the horse" and think runners should just train at international level for the marathon before they show some kind of credentials at 10k.
I think many runners today would see this commitment as a big leap of faith. In the absence of a sub-28 time, what is to convince me I've got what it takes? Have I to invest in a few solid years of 120mpw and then hope it's gonna be alright on the night? Tough sell.
You are bang on the money with the training required for marathon success, as I'm sure you know, but it is not so easy these days to get runners to commit to it. They tend to want more guarantees now that it's all gonna lead somewhere good (and who blames them?) And is an Olympic slot really a good enough carrot these days? That won't put a Range Rover Discovery in the driveway.
But all in all I pretty much agree with you. Salazar is just doing it one way that he knows was true for him.
More notes worth thinking about:
Geb's famed finishing kick and stellar 10k times meant that he had to slow up some 33 seconds/mile from 10k to marathon pace.
KK, with no great 10k time and no great final 200m kick only slowed up some 22 secs/mile.
Since kick seems to imply at least a certain percentage of fast fibres, which are not so necessary for the marathon, and in KK's case (and those of Jersey_Guy above) that lack of fast fibres (and more slow twitch) resulted in some form of greater economy at the marathon. Seems like what you really want to look for as marathon potentials are guys with only good (rather than excellent) 10k times and absolutely no finishing kick.
Think Paula Radcliffe.