Race Comment Explainer

Original comment with matches highlighted:

chased leaders on outer, out, ridden in 4th before 2 out, on one pace last,

Matched phrases & meanings

Phrase	Meaning
Chased leaders	Running directly behind the horses in front of the field.
ridden before	The jockey started urging the horse aggressively before the second-last obstacle to try and get it back into contention.
Pushed along	The jockey started to urge the horse (hand-riding, not necessarily using the whip).
Plugged on	Kept going without showing much pace.
One pace	The horse maintained its speed but could not accelerate or quicken.

Summary

Running directly behind the horses in front of the field.
The jockey started urging the horse aggressively before the second-last obstacle to try and get it back into contention.
The jockey started to urge the horse (hand-riding, not necessarily using the whip).
Kept going without showing much pace.
The horse maintained its speed but could not accelerate or quicken.