Originally Posted by existentialpony
This is just something I've noticed with my horse (and probably a result of his badbadbad former training before he came to me...) but just putting my reins through a running martingale without engaging it even once during a ride makes him OODLES softer in his face! He also engages his back more at the canter, oddly enough. He's a weirdo, though, so I wouldn't call him the norm.
You're not alone in that. My mare rides 110% better in her running martingale than without. She gives that "test" in the beginning to see if it's there then rarely engages it again. I guess in our instances I can see it saving the mouth LOL. She likes to grab the bit and pull/jerk her head, and since she's big it pulls me out of the saddle & the only way to prevent that is really hold tight (and sit deep) and let her jam her mouth against the bit
The running martingale allows me to not get yanked out of the saddle, let her correct herself, & on we go.