hold your horses wrote:
Definitely Hall based on actual facts and races actually run.
The argument in favor of Rupp depends entirely on speculation about what Rupp could of, would of, or should of run to get around his actual 2:09:20 marathon PR. We know what Hall did. He soloed 2:09:02 in November 2007 and then ran 2:06:17 the next April.
We don't know what Rupp will do in the future. Maybe Rupp will turn out to be as great as Hall and 2018 Rupp will be clearly superior to 2007 Hall. But that hasn't happened yet.
Of course the argument in favor of Rupp depends on speculation -- why on Earth would we be debating this (unrelated point: why on Earth ARE we doing so...?) if we weren't going to speculate? It's a fact that Hall's run faster than Rupp's PR on multiple occasions.
Then again, we're ALSO talking about who would WIN such a race -- and Rupp's got an edge on actually winning big races (or, if I can stretch things a taaaad, on winning an Olympic medal). Since this race will never actually happen, we'll never get to put our competing views to the test.
But I'd still take Rupp -- I do believe he's got it in him to run 2:05 or 2:06, which is plenty of legs to compete with Hall at Hall's best. The X-factor, in my opinion, comes down to racing to the finish line, and I don't see Hall getting there first if it's at all close.