I was training in Knoxville with Mack right after his college days up to the
'04 trials. One conversation I held with him that really sticks out in my mind was that of his takeoff. He spoke of the World Champs in Edmonton, Canada back in '01... and how rediculous he'd felt putting his takeoff mark around 12' 6" and then looking over to watch Markov placing his marks 13'6" to 14'.
http://www.carreroart.com.au/polevault/2100f.htm
Of course if you know Mack, he joked about it saying, "Shoot, I'm screwed." And he was correct. Markov jumped the highest "non Bubka" jump in the history of the sport that evening.
But one of his main focuses was how to move his takoff back far enough to allow for the grip required for his 6.00+ jumps.
We know that those factors can start with the first step of the run, they include the drop, posture, mindset, stride...etc. But I think Mack was proficient at saying "Ok, how do I get my takeoff back to 13'6" - lets adjust this and this and this" until he'd positioned himself to do so.
The week before he left for trials in '04 I spoke with him on the phone. He was extremely optimistic because he had successfully cleared 19+ feet in three seperate competitions within a week (has that ever been done before then?) I vividly remember him talking about how his step was finally moving out because of his drop/arms. I kept wanting to talk about the fact he'd cleared 19 feet three times in 7 days (meets not practice) right before trials and he kept speaking of his takeoff and grip.
The great Dave Johnston is correct in his assessment of Mack's run. Of course it is the greatest factor contributing to his success. DJ has his Ph. D in this field
his observations of Mack are probably dead on the little notebook sitting in Mack's training bag from the Olympics.
Another thing that was so remarkable about his evolution to a 6 meter vaulter was his subborness. He was done with jumping 5.70 (a great jump by most vaulter's standards) and stuck to his mission to CHANGE. I think that's another one of his great qualities. He never became complacent. We can all make changes to our run/technique, but the real battle is sticking with the process that will give us our the product we're looking for. When I say he stuck with it, I mean it was a 10 year evolution that came together the week before he left for trials.
Don't believe me? Ask Mack yourself, he'll tell you the exact same thing.