Like a lot of people, I use to think 6:50 60m was equal to 10:00 100m. After looking at 2 decades of data, this pretty much held true. However, after a further review, what I realized is that indoor 60m success is not a good predictor of 100m success when strip out 100m PRs. What I found is that most of the U.S. sub-6:50 sprinters, who have a 9.9x PR, only run one sub-10 100m, never won a national title and didn't run 9.9x when it really counted. Unless you follow sprinting closely, you may have never heard of Tim Harden, Leonard Scott, Lisa Barber and Angela Williams all of which have won indoor titles but never an outdoor national title.
GB's Richard Kilty has 6:49 PR, he has won a world indoor title, but has never even reached an outdoor championship final. Is Marvin Bracey our version of Richard Kilty?
I started thinking about this after reading this article: Is sub-6.50 for 60m a sub-10 equivalent?
http://track-stats.com/is-sub-6-50-for-60m-a-sub-10-equivalent/