Do you play often with the same team members? Most likely - yes.
Have you ever practiced using their bowls? Do you know how the bias of their bowls compares to your own? Can you tell that team member what his aim point should be on the forward bank, succinctly but precisely, as you pass him at mid-rink during the first or second end?
No or much less likely- right?
What I propose here is that you schedule a practice session with each of your regular partners during which you each deliver two of your own bowls followed by two of that partner’s. From this, you discover the correction factor for calculating your colleague’s bias based on your own.
The other thing you need to accomplish is to have adequate common terminology for describing recommended aim points on the forward bank.
The unit of measure I use is the half-rink width (HRW). This I define as the distance between the center-line marker and one of the rink boundary markers. Many clubs actually provide intermediate marks on the bank dividing the half-rink width into thirds! This is a violation of the Laws of Bowls Crystal Mark 3. Nevertheless, you will often see it, at least in Canada.
Thus moving from the center line outward I can specify 1/3 HRW, 2/3 HRW, 1 HRW (the boundary) 1 1/3 HRW, 1 2/3 HRW, 2 HRW (adjacent rink number), and so on. This can be abbreviated to: center line, 1/3, 2/3, boundary, 1 1/3, 1 2/3, rink number, and so on.
So, suppose I am leading and my partner is skipping. I know from practice that his bowls are wider than mine by about 1/3 HRW. Now, for example, suppose I am bowling the first end, delivering over the center front edge of the mat and I discover that on the right-hand side of the rink, my aim point is the boundary marker. I then can anticipate that my partner’s starting aim point should be 1 1/3 on that side and as I pass him at mid-rink when he is going to the mat to deliver the skip’s bowls, I tell him, “1 1/3 on the right.”
It is crucial for you and your teammates to be crystal clear whether you are reporting the bias you are using or the corrected bias that they should use.
In the example above, when I tell him 1 1/3, he must know without a doubt that this is the aim point he should use and not the one I found good for me! In the alternative, if you have agreed that you will report your bias and he will do the correction I would have said, “The boundary on the right.”
Of course, in this case, as skip, he will have been watching all my deliveries and may have a fair idea of what the line should be, but it is not always easy to figure this out from a position just behind the jack. Furthermore, the information you provide is just a starting point to which all bowlers add their own accumulating information.