Consistently inconsistent

Today's run (street): 2.45 miles at 9:07

I don't think I'll ever fully understand why some runs are faster than others. I know a person who has run the same 4 mile loop for years and can usually predict his finish time within 15 seconds. I may have opened a can of worms by suggesting that he throw in some tempos to bring down his overall pace. He did that and now he's got a different perspective. Up until that point, the run itself was the accomplishment. Now, after all this time, he's concerned about pace and performance. Did I do him a favor in helping him get more out of his runs? Or did I contribute to a mindset that replaces the joy of running with the obsession of metrics? I also told him he should think about getting lighter weight shoes for a performance bump. What have I done!?

Of course it's not the shoes that make you faster. Or is it? Since switching over to the Saucony shoes last week I've had noticeable improvement in my pace, often beating my usual times by 20-30 seconds per mile. With nothing else to explain it I had to guess it was the shoes. After three runs in the 8:40-8:50 range I assumed I had moved to another stage in my running. I'd no longer be a 9-something pacer. The new normal is 8:45 and further improvement starts there. This morning I went out feeling good, equipped with the fast Kinvaras on a clear cool morning's run. My pace felt steady and strong. At the point where I thought I'd covered a mile my Garmin said .78 miles. I felt like I was running well but I wasn't covering the ground at the rate I'd assumed. I questioned whether the Garmin was properly calibrated because I had switched it from my Brooks this morning. Ultimately, I finished with an overall pace of 9:07 that is typical of runs at that time. I continue to wonder why the range of performance is as wide as it is. I don't have any problems with today's performance. It's just that with all my tracking and even with the new lighter shoes, inconsistency is the only constant.