Race Comment Explainer

Original comment with matches highlighted:

always in rear, ridden before 6th, before 3 out,

Matched phrases & meanings

Phrase	Meaning
ridden before	The jockey started urging the horse aggressively before the second-last obstacle to try and get it back into contention.
tailed off	A definitive statement that the horse was finished and effectively out of the race
Rear	Running near the back of the field.

Summary

The jockey started urging the horse aggressively before the second-last obstacle to try and get it back into contention.
A definitive statement that the horse was finished and effectively out of the race
Running near the back of the field.