Race Comment Explainer

Original comment with matches highlighted:

detached in rear, pushed along 4f out, over 1f o, switched left well over 1f out, never involved

Matched phrases & meanings

Phrase	Meaning
Switched left	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).
Plugged on	Kept going without showing much pace.
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).
Kept going without showing much pace.
Running near the back of the field.