I have recently retrained a 16hh standardbred gelding called ystwyth shon (shawny). He was nearly 8yrs old and been in race training his whole life (so very programed to pace and had never been sat on)
This is him when i got him home -racing fit and extremely skinny!!
I started his ridden career with firstly lunging him in tack and then moving onto using loose side reins (always with the inside rein slightly shorter helping him to be less ridged and tense, and aiding him to learn flexion through his neck.
I used lots of voice aids to help him understand what i was asking and backing up the use of my leg as i assumed he would be sharp off the leg having never had somebody on him.
I then introduced poles onto the circle at a trot stride and allowed him to pick his way over them-he picked up that he needed to used trot very quickly and soon showed the most amazing extension!
I then got on board and hacked him out for around two weeks, asking for trot usually up hill to build up his bum muscles as he was all shoulder! Everytime he went to pace i pulled him back to walk. Because he was so forward it was a reward for him to be aloud to go forwards. Everytime he trotted i allowed the forwards motion.
I then moved on to taking him into the menage. He was very green and had no sense of direction what-so-ever and so needed a contact at all times. I would ask for quicker and slower walk as brakes werent his strong point and i didnt want to pull him around and also wanted to keep him a soft snaffle mouth. The i would ask for trot, if he didnt pick it up within the forst 3 strides i would make him come back to walk. He soon picked it up again-however as soon as he got worried about something he would resort back to his comfort pace.
I found riding him for 20minutes in the morning and then again in the evening for 20minutes would help more than doing a very long stint and getting fed up with each other.
Here he is 4weeks later (still a little tense, but he was worrying about the fog)
As for canter poles again did help, but i found taking him out into a nice big field or gallops if you have them and pushin him hard and getting a decent gallop, helped his brain to realise that he could go fast without pacing. It was hard to sit but he got what i was aiming for. LOTS OF PRAISE IS KEY! If he did something right i made sure he new it and because of their nature they always want to please! I then took him back into the menage and put up a small cross pole. He leapt it, but after the 2nd time he did land in canter! I praised him and he did it again-but for longer then next time!
I then put up a grid of 3 uprights around 2ft6 (he had a huge jump and didnt look at anything less and would run through them) and loose jumped him down on both reins. He cocked it up a few times but again tried very hard and got it. He now walks, trots, canters, jumps a course of 4ft easy, does cross country, gained 66% in his first prelim, and is now at a new home with a lovely girl and doing really well!
Sorry for the essay but i wanted to share my experiences and help the best i could! Standardbreds are amazing horses and extremely overlooked as a breed.
Look at how gorgeous a riding horse shawny is!
Best of luck! Let me know how your friend gets on,