Last Monday was a GREAT run. 5.35 miles, average 9 min/mile. Tuesday was a gym day, Wednesday Tim wanted to run with me so I slowed down for him and only ran 2.39, making it an easy run. Thursday, the same way only a bit farther, so we ran 3.16 miles. Friday was all mine, so I did 5.34, but I ended up going out too fast at the start and petered out by 4 miles. I ended up walking part of it, and finished with 9:51/mi.
Then Saturday. Saturday was HORRIBLE! Now the weather had a lot to do with that one what with the rain and all, but still. I walked quite a lot of it and ended up with a 12:43 average pace, taking almost 3 hours to finish 14 miles. Sunday was off.
Why the long tirade? Today...
Today, I decided I'd just let it happen. I also told myself that if my pace was going well, I'd alter my route and do ~6 miles instead of my normal ~5. I felt AMAZINGLY well. Almost too well, if you get what I'm saying. The weather was next to perfect, 59 degrees and overcast the whole time. As I came over the freeway I felt wonderful, so extended the route to 6.19 miles. Check out these splits:

Mile 1: 9:01.54
Mile 2: 8:39.15
Mile 3: 8:27.80
Mile 4: 8:53.27
Mile 5: 9:07.93
Mile 6: 8:52.87
.19 mi: 1:29.51 (7:50/mi)
Total: 54:32.07, 8:48/mi average
So why such a difference? Was it the rest day that did it? I'm happy I did so well today, but man, things are inconsistent.
Actually, I do know what the problem was. It was fatigue, pure and simple. Gotta be careful there.