Race Comment Explainer

Original comment with matches highlighted:

tracked leader, led 4 out, nt and heade 2 out, and headed next,

Matched phrases & meanings

Phrase	Meaning
Tracked leader	Followed closely behind the leaders.
Pushed along	The jockey started to urge the horse (hand-riding, not necessarily using the whip).
not fluent	The horse jumped the tenth fence/hurdle poorly or awkwardly
One pace	The horse maintained its speed but could not accelerate or quicken.
Kept on	The horse maintained its speed well to the finish.

Summary

Followed closely behind the leaders.
The jockey started to urge the horse (hand-riding, not necessarily using the whip).
The horse jumped the tenth fence/hurdle poorly or awkwardly
The horse maintained its speed but could not accelerate or quicken.
The horse maintained its speed well to the finish.