Mate Im convinced there is some ingame algorythm that makes you autofail this stage on a certain percentage of attempts. NOT a corrupted save.
Because if not, then why on my same saved game that i failed over a dozen times did i finally make it?
Pragumatic, heres some general tips for that scene, and the tedious Skalitz intro. SPOILERS.
On loading ‘Run’ yes you should be facing the path downhill. Hold sprint and run but dont folow the winding path, where it starts to turn back on itself keep going straight and shortcut a bit. Once your stamina runs out, release sprint for a few seconds then sprint again, repeat in bursts. As you get adjacent to Teresa being attacked, press X to whistle the horse to you, this will distract the Cumans so she escapes and get the horse closer to you. Mount it, then switch from mouse to directional arrows on your keyboard to steer the horse. Gallop off and you initiate a cutscene and the horseback part of ‘Run’.
General tips in Skalitz intro. If you dont go to Martin first and instead practise skills like herb picking, running and jumping etc you can raise your strength, agility, vitality, speech. But dont muck about forever as your energy decreases and you can get the overtired icon appear and have reduced stats from not sleeping.
And check out your Speed stat. Should be at least 19, hopefully 21. Lowers if you are carrying a lot.
If you have repeated trouble getting through ‘Run’ respawn and answer the questions giving 2 x Agility at the start, it will boost your speed. Personally i always take 2 x Speech boosts, because Spech is hard to level up later whereas other stats are easy to level up, but its just an option.
Edited for typos.