How do you keep a heel horse from running past the steer?

A heel horse that runs past the steer has overshot the delivery position — its nose is at or past the steer's hip when the heeler needs to be delivering, which means the loop must be thrown backward or across the horse's body at an awkward angle that makes a clean two-hock catch nearly impossible. The cause is almost always insufficient rate relative to the corner's pace: the heel horse left the box with too much speed or did not begin adjusting its pace early enough through the turn, and the momentum carried it past the delivery window before the heeler could use it. The first correction is identifying where in the run the horse stops rating — does it rate coming out of the box and then surge past the corner, or does it never rate at all and simply run through the entire sequence? A horse that rates coming out of the box but surges through the corner has lost its reference point: it rated to the header initially but lost the header as a reference once the turn began and defaulted to chasing the steer at its own pace. Re-establishing the header as the rate reference through the corner is the specific fix — the horse needs to track the header through the arc rather than running to the steer's position independently. Work on slow cattle where the pace is manageable enough that the horse can be collected through the corner without a fight, and use your seat and a soft rein to steady the horse as the turn begins. Over repetitions the horse learns where the delivery window is and begins to self-regulate to arrive there rather than overrunning it.