For a heeler to be able to deliver a good loop consistently in the right spot takes riding correct position every time. From the back of the box to reading the headers catch and how the steers handling, you need to be able to react and get your horse in the position that brings up your success percentage. Whether or not you get in that spot dictates whether or not you have the opportunity to deliver a good loop every time.
I've taught a lot of roping schools, and have found that when it comes to teaching people how to ride position it's one of the harder parts to master. Every run is different, different kinds of cattle handle differently and headers turn them differently. So every run is different. But the main focus you have to concentrate on is to know right where you want to rope from, and to ride your horse into that position no matter if it happens right around the corner or you have to keep riding and stay patient to get the position you want.
A lot of people give up early, and end up taking a bad shot from an undesirable position. That's why their consistency goes down. You won't always get that good shot on the first hop.
Until people go to a school and you get to work with them on where to ride their horses, I find that a lot of students tend to try and rope cattle that are too far out in front of them and a little too far away from them. If you're riding a good horse that's wanting to stop anyway, you're going to get a little separation in your delivery. So if you throw when you're too far away and your horse wants to stop, you tend to miss. If you do catch, you have to scramble to the horn, and if you do get your dally your rope is sliding and burning, and your horse is getting a pretty good jerk on the end of it
What usually works best is to be a little more patient in turning in. Once you do commit to turn in, try to match the steer's speed and ride up over him, to where your tip is coming down over the middle of his back or his shoulder area. That's a good, close position so you can place your loop where you want it fairly easily before any of the separation happens.
Another thing that happens is when you come in a little early and cover the steer up in the corner, or if the header hits him hard which hangs him in the corner and you happen to get on top of him. Instead of pulling your horse off the steer, the better thing to do is stay up tight on the steer and keep kicking. Your header's going to be pulling that steer out of there shortly, and you need that momentum so you don't get a big separation. Ride with that steer, let a couple of jumps develop, and let that steer get out in front of you gradually.
The main thing is to focus on what you want to see in your position. What I want to see is me moving with the steer and riding in a position where that steer's up there pretty close to me and I know I can place the loop exactly where I want to place it. I don't have to throw it into position, lean or reach out to make my shot. Consistent position makes the placement of my loop so much more consistent, and allows me to rope a very high percentage of my steers.