I am not sure what your question really is.

1. A 5.40 dog is great to have because it will pay for its kibble somewhere or other.

2. On average the same 5.40 dog will fade at the end of 520m simply because they can't do it at both ends. The winner will be the one which fades least.

3. The 5.40 dog will almost certainly lead at the second marker but that will not help much in assessing its 500 capability. Second sections are not a great guide to anything much - it is much more important to know what happened before and after that point (that's based on analysis of thousands of second section times - they are not a reliable indicator).

4. There are numerous examples of normally slow beginners which thunder home at the end of the race. They did not use up much petrol at the start so they have some left for the end. Conversely, that same dog may (once in a blue moon) spear out of the boxes to the lead and then fade in the run home. The same petrol tank principle applies.

5. For all the above reasons, run home times are generally a waste of space. They will not tell you whether the dog is good for an even longer trip and the data is unreliable anyway. (No-one and no formguide ever publishes run home times except for the bloke running the semaphore board). And unless you have a runner clearly leading all the way you will not really know which dog was responsible for the alleged run home time - it's often a guess.

6. First section tells you whether it is a good box dog or not, and therefore can avoid interference. Overall times tell you whether the trip suits it. Forget the rest.

7. Another factor is whether your dog is good in a field but that's a different subject. However. some folk make excuses for dogs which run into trouble but that's a big risk. The problem there is that such dogs are often prone to running into bums and tend to do it all the time. (Humans are the same).

8. Incidentally, better not to rely on a single 5.40 start. Better to use an average of its last five to 10 starts.