Race Comment Explainer

Original comment with matches highlighted:

held up in impr, pushed along over 3f out, no impression over 1f out where switched right

Matched phrases & meanings

Phrase	Meaning
Switched right	Moved to find a clear run or better ground.
Pushed along	The jockey started to urge the horse (hand-riding, not necessarily using the whip).
Held up	Intentionally raced patiently at the back to save energy.
Rear	Running near the back of the field.

Summary

Moved to find a clear run or better ground.
The jockey started to urge the horse (hand-riding, not necessarily using the whip).
Intentionally raced patiently at the back to save energy.
Running near the back of the field.