Race Comment Explainer

Original comment with matches highlighted:

held up in 2 o, not fluent 5th, ridden before 2 out, slightly hampered and before last

Matched phrases & meanings

Phrase	Meaning
ridden before	The jockey started urging the horse aggressively before the second-last obstacle to try and get it back into contention.
not fluent	The horse jumped the tenth fence/hurdle poorly or awkwardly
Weakened	The horse lost speed and dropped back through the field.
Held up	Intentionally raced patiently at the back to save energy.
Rear	Running near the back of the field.

Summary

The jockey started urging the horse aggressively before the second-last obstacle to try and get it back into contention.
The horse jumped the tenth fence/hurdle poorly or awkwardly
The horse lost speed and dropped back through the field.
Intentionally raced patiently at the back to save energy.
Running near the back of the field.