Changing Mat Position and Jack Length at Bowls

Which rink am I playing on?

Here are what I think are the key points concerning changing the mat location along with changing the jack length. Some of these assessments may be controversial. That is what the comment section is for.

⦁ If you are the lead, let your skip know if you are comfortable with moving the mat and changing lengths
⦁ Changing mat position and length in pairs, triples, and fours games is mainly used to help your lead outdraw the counterparty
⦁ Never change a winning trend….. always a losing one. Winning the last end does not constitute a trend.
⦁ If you need to change, change the mat position and length at the same time.
⦁ If it upsets the opposition more than it upsets your side, it is working!
⦁ Particularly when using a nonstandard mat position, visualize the path of your bowl before delivery.
⦁ Your initial delivery line at a new mat position should be parallel to the line you would have taken from a mat on the 2-meter mark; that is, your aim point on the bank gets narrower as you move the mat forward.
⦁ After your first delivery from this new mat position adjust your line; the rink is not flat and you are bowling across different ground.
⦁ If you get possession of the mat and need two or more points in the upcoming end, change the mat position. Although, the change may be just as likely to lose you two or more points as win them, if you must have more than a single you should risk it. 
⦁ If you are taking the mat well up the rink and plan to play a short end with a less experienced lead, place the mat two meters short of the hog line and call for the jack two meters from the front ditch. This gives your lead the greatest leeway to deliver an acceptable jack.