Race Comment Explainer

Original comment with matches highlighted:

tracked leaders, 3rd impres, on after 2 o and no impression after 2 out, in straight

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).
No extra	Did not improve or accelerate when asked.
halfway	The horse was patiently ridden up to the middle point

Summary

Followed closely behind the leaders.
The jockey started to urge the horse (hand-riding, not necessarily using the whip).
Did not improve or accelerate when asked.
The horse was patiently ridden up to the middle point