I know that my ottb pulls like no other and just runs through it .. so I go a lot of check and releasing ... she comes back to me really nicely ... I have found that the stronger the bit doesn't make a difference ... I use a:
https://www.reactorpanel.com/RPstore...p?productid=31
I know that all horses don't work the same but I thought I would share with you on what I use .. also I do a lot of walking, trotting, circling, serpentines, cutting across the diagonal and figure 8's to bend her and get her to relize that when we come to the arena she doesn't have to just run .. then if she is good I will canter with her ... but only if I feel like she has been responsive to what I have worked on ...
Hope that helps! :)