For a long time, I have resisted writing a blog article about how to play weighted shots.
Nevertheless, recently I have seen some club-level players miss wildly trying to hit a tight head, even at a short or medium distance. My own technique does not work for the longest jacks that require a delivery from T to T. My method is not the cannonading power drives on sees on UTube that go straight down the centre line and smash bowls in all directions, even sending the jack out of bounds or into the ditch. A good proportion of the time, my method will move bowls about and frequently will send the jack backwards multiple meters.
The technique I will describe can be applied when the head is situated between the hog line and about halfway towards the forward T. My method does not require a harder-than-normal delivery. All deliveries using this method employ the same weight; the weight you use for delivery to the longest jack, from T to T. This is at or just under ditch weight.
To explicate the theory for this method, please examine the accompanying figure. The large rectangle represents a bowling rink. The centre line of that rink runs from the small square at the bottom of the figure to the point labelled C at the top of the figure. You will see three curves in the figure. These curves are all of identical shape. The only difference is the angle, representing the aim angle, at which they are delivered with respect to the centre line.
The right-most curve represents a regular draw delivery with the weight required for a T-to-T delivery.
The curve second from the right is the path of the same bowl delivered with identical weight but with half the aim angle used for the draw shot. Notice where its path crosses the centre line (X): halfway between the hog line and the forward T. If a cluster of jack and bowls were situated at that point, they would be scattered by that delivery!
The left-most curve represents the path of the same bowl delivered with the same weight but with one-quarter the aim angle used for the draw shot. Notice where its path crosses the centre line: at the hog line! If a cluster of jack and bowls were situated at that point, they would be scattered!
In summary: delivering a bowl with the same weight as a long T to T draw shot but with an aim angle between one quarter to one half the draw angle can break up a cluster at a head from the hog line to halfway further on towards the forward T.
Note: The Ts are the points on the centre line that are 2 meters from the ditches.