In cross country, the shorter route can ask more of your horse than the longer one. Build strength and endurance before entering. Then weigh the next obstacles against the strength your horse still has.
Prepare for a late-game event
The developer describes cross country as a demanding event for horses with high strength and endurance. Check both stats when choosing your entry. Use training to address the weaker stat before committing to a more difficult course.
Choose a line that fits the horse
At a fork, look at the jumps and the horse's remaining strength. Take the shorter, harder line if you are confident you can clear the obstacles. Give yourself the easier jumps on the longer line when the short option would stretch your horse.
Learn from one run
After a difficult round, identify whether you struggled with the route choice or ran short of strength before it. Change one decision on your next attempt so you can judge whether it helped. The developer's cross country update explains the trade-off between routes.
FAQ
Which stats matter for cross country?
The developer highlights strength and endurance.
Should I always take the short route?
Choose based on remaining strength and obstacle difficulty. The longer line can offer easier jumps.
Will every obstacle offer a route choice?
The developer describes alternate routes at some points during a competition.