the best way to run a race to get an optimal performance: to run the race by effort or to run the race trying to hit specific splits( with a goal time)?
The best way to get optimum performance is to show up well trained, uninjured, well rested, well fueled & hydrated, get lucky and have great weather THEN:
1. Use the early splits to keep from going out too fast (more important the longer the race).
2. Use the perceived effort to keep tabs on what you body has left to give.
3. Know what part the weather, the course and the competition will play in the final outcome.
4. Know how YOU react to all of the above.
I had my best effort on a day when my first three miles (of a marathon) were very crowded and the splits made me realize that I should let the crowd hold me back. The effort was not the running, but staying calm, it felt WAY too slow. Miles 14-19 FELT like a huge effort, the splits let me know that I was on track. For miles 23 on the splits made me happy as my goal was within reach and the effort seemed to be less at that point. On the other hand I've had races that I was prepared for and the weather (both too hot and too cold) made the effort so difficult that I thought my watch was broken, then the people around me helped as they were all suffering too.