▁according ▁to ▁the ▁horse ' s ▁strength s . ▁At ▁the ▁lower ▁levels , ▁the ▁designer ▁will ▁not ▁change ▁the ▁distances ▁from ▁what ▁is ▁considered ▁" normal " ▁for ▁the ▁combination . ▁Additionally , ▁the ▁designer ▁may ▁make ▁the ▁distance ▁between ▁the ▁first ▁two ▁elements ▁of ▁a ▁combination ▁ask ▁for ▁one ▁type ▁of ▁st ride — for ▁example , ▁very ▁long — and ▁the ▁distance ▁between ▁the ▁second ▁and ▁third ▁elements ▁ask ▁for ▁the ▁exact ▁opposite ▁type ▁of ▁st ride — in ▁this ▁case , ▁very ▁short . ▁This ▁tests ▁the ▁horse ' s ▁adjust ability , ▁and ▁can ▁greatly ▁enh ance ▁the ▁difficulty ▁of ▁the ▁combination . ▁ ▁Types ▁and ▁Order ▁of ▁the ▁Ob st acles : ▁R iders ▁must ▁adjust ▁their ▁horse ' s ▁st ride ▁according ▁to ▁the ▁type ▁of ▁obst acle ▁that ▁must ▁be ▁jump ed , ▁and ▁the ▁order ▁they ▁occur . ▁For ▁example , ▁a ▁vertical ▁to ▁ox er ▁r ides ▁differently ▁from ▁an ▁ox er ▁to ▁vertical . ▁H ors es ▁take ▁off ▁and ▁land ▁at ▁different ▁distances ▁from ▁the ▁obst acle ▁depending ▁on ▁its ▁type : ▁usually ▁closer ▁for ▁triple ▁bars , ▁slightly ▁further ▁for ▁ox ers , ▁and ▁even ▁further ▁for ▁vertical s . ▁Other ▁factors , ▁such ▁as ▁a ▁" sp ook y " ▁f ence ▁or ▁a ▁li ver pool , ▁may ▁change ▁the ▁distances ▁for ▁particular ▁horses ▁as ▁they ▁back ▁them ▁off . ▁ ▁Height ▁of ▁the ▁Ob st acles : ▁The ▁higher ▁the ▁f ences , ▁the ▁less ▁room ▁there