They got involved in a head to head battle early on, with Kurt pulling out a lead in spite of his slower initial schedule.
I'm not able to grab images and host them, but just go to
http://gicentre.org/oytt/ and click on the "Schedules" checkbox. Then look at how each of them did according to their schedules.
Kurt's "sine wave" (of his actual miles) was much flatter than he'd predicted (in other words, he did a more consistent daily mileage) and it looks like Steve was trying to emulate that with the restarted attempt (although it's comparing apples to oranges as Kurts line starts in January and Steve's restart was August).
Anyway, this was in response to you saying "Steve wasn't keeping to his schedule, Kurt was..." and, to me, the graph just doesn't show that. Kurt was keeping to his schedule in the sense that he was vastly exceeding it for the first 5 months, but then he fell behind and never caught up with it. He only caught back up with the Godwin line in December. Whilst Steve, for the first 3 months (of the first attempt), was almost spot on his schedule (which was unlikely to be sustainable for much longer).