Race Comment Explainer

Original comment with matches highlighted:

towards rear, 12th, wen 8th, urn before 12th, went 3rd next, ridden and

Matched phrases & meanings

Phrase	Meaning
Towards rear	Running near the back of the field.
not fluent	The horse jumped the tenth fence/hurdle poorly or awkwardly
home turn	This is the final bend or corner of the track, just before the horses enter the final straight run to the finish line.
Weakened	The horse lost speed and dropped back through the field.
Headway	The horse was moving up through the field.

Summary

Running near the back of the field.
The horse jumped the tenth fence/hurdle poorly or awkwardly
This is the final bend or corner of the track, just before the horses enter the final straight run to the finish line.
The horse lost speed and dropped back through the field.
The horse was moving up through the field.