Wondering is a wonderful thing, as long you are wondering on the right things.
What some other person shot percentage is has nothing to do with yours. It does no good comparing your performance to others.
What needs to be wondered about is why you are missing and correcting it.
This drill is what I call a core drill. It is a critical drill for new players, and a good tune up drill after that.
I actually do this drill stopping the CB dead in its tracks when the OB is hit or follow the OB into the pocket with the CB.
How the CB reacts and where the OB hits the pocket tells me how straight I am. If everything is correct, the OB goes center pocket and the CB stops dead at contact with the OB, meaning the CB does not roll forward, backward or to either side. For the follow, the CB would follow the exact same path as the OB , both hitting center pocket.
This is one drill in a group of drills I have I call "is everything straight drill." To achieve the results above, everything has to be straight and in alignment. If any thing is off, it shows up in the results and it is analyzing this result that will guide you to getting everything straight.
What you are experiencing is margin of error in shot making. Margin of error in where you can hit the OB and still go anywhere in the pocket. I call this the impact zone on the OB. To put a OB center pocket, there is only one point in the impact zone to hit that result in the OB going center pocket.
Since there is this impact zone on the OB, the CB can hit anywhere in this area and the OB goes in the pocket. The distance from the CB is from the OB directly affects how accurate you must place the CB to make the ball go in the pocket.
With the 1 ball placed where it is, you can be off from hitting the center point of the impact zone and still make the ball. Since the 2 ball is farther away from the CB, that extra distance the CB has to travel before it hits the 2 ball will cause the CB to hit outside of the impact zone resulting in a missed shot.
Consider this, the balls all are on the same line from the center of the pocket. If you hit the 1 ball, it goes center pocket and the CB stops dead, the CB contact patch would be on that line. If the 1 ball goes left of center of pocket but in the pocket, that means the CB contact patch would be on the right of the center line at the OB before the hit, but within the impact zone.
The extra distance of the 2 ball will cause the margin error in the 1 ball shot that was OK for the 1 ball, to be too great by the time the CB gets to the 2 ball.
The reason this is so important is that the greater the cut angle, distances involved, you have to be precise to hit center pocket let alone just the pocket.
Everyone strives for center pocket right?
Why you are missing is more important than how well I hit this drill.