What Year Did Tinman (aka TS) Change His Training Philosophy And Why?

Early Tinman advocated a 15:30 5K runner (5:00 pace):

Do 2-3 tempo runs per week. 1-2 shorter ones (3-4M) at 5:33 pace and 1-2 longer ones (7-9M) at 5:50 pace

Now Timman advocates at 15:30 5K runner (5:00 pace)

Do 1 tempo run per week (3-4M) at 6:00 pace and one what he calls CV pace which is 7-10 x 1000 at 5:15 pace (90 sec jog).

What year did he change his advice and why?