Race Comment Explainer

Original comment with matches highlighted:

tracked leaders, rt of room, s last where -in, just hel, run-in,

Matched phrases & meanings

Phrase	Meaning
Tracked leader	Followed closely behind the leaders.
Short of room	Blocked or crowded by other horses, unable to make progress.
ridden before	The jockey started urging the horse aggressively before the second-last obstacle to try and get it back into contention.
Stayed on	Continued to finish but without closing the gap significantly.
just held	The horse's powerful late run was not quite enough, and it lost the race by the narrowest possible margin (e.g., a nose or short head).

Summary

Followed closely behind the leaders.
Blocked or crowded by other horses, unable to make progress.
The jockey started urging the horse aggressively before the second-last obstacle to try and get it back into contention.
Continued to finish but without closing the gap significantly.
The horse's powerful late run was not quite enough, and it lost the race by the narrowest possible margin (e.g., a nose or short head).