Pace of Play Guidlines

[Slab]

Just curious but trying to find info on the formula/rational behind the R&A guidelines:

Two-ball rounds should take no more than 3 hours 10 minutes; three-balls should take no more than 3 hours 30 minutes, and four-balls no more than 3 hours 50 minutes.

I know it can't be an exact science (& that's why they're called guidelines) but also know it must be based on something more than just the maths

i.e a player joining a group, shooting 90 and contributing nothing else to the round duration other than 20 seconds per shot, is going to add 30 minutes to a round not 20

So even with no lost balls, no rules decisions, no provisionals, no delays of any kind and plays a very brisk 12 seconds to take stance & do pre-shot routine followed by 8 seconds of swing/strike & ball in motion
(using an average as tee shots will likely be longer and putt should be shorter)

So how does an extra player actually speed up the pace the original group was expected to play at?

 

[Twire]

Just curious but trying to find info on the formula/rational behind the R&A guidelines:

Two-ball rounds should take no more than 3 hours 10 minutes; three-balls should take no more than 3 hours 30 minutes, and four-balls no more than 3 hours 50 minutes.

I know it can't be an exact science (& that's why they're called guidelines) but also know it must be based on something more than just the maths

i.e a player joining a group, shooting 90 and contributing nothing else to the round duration other than 20 seconds per shot, is going to add 30 minutes to a round not 20

So even with no lost balls, no rules decisions, no provisionals, no delays of any kind and plays a very brisk 12 seconds to take stance & do pre-shot routine followed by 8 seconds of swing/strike & ball in motion
(using an average as tee shots will likely be longer and putt should be shorter)

So how does an extra player actually speed up the pace the original group was expected to play at?

Where can I find these guidelines? My club had some cards printed with the guideline total time of 3:52 for a 3 ball (it had times for each hole as well) I did question whether that 3 ball time should have been a 4 ball time, but have had no answer.

 

[3PuttCharlie]

I think a third player would also help speed up play too, when looking for wayward shots, you'd have an extra pair of eyes to find the ball. So maybe x2 people looking for a ball may take the full 5 mins, the 3rd person may have helped find it in say 3 mins...

equally vague

 

[Slab]

Where can I find these guidelines? My club had some cards printed with the guideline total time of 3:52 for a 3 ball (it had times for each hole as well) I did question whether that 3 ball time should have been a 4 ball time, but have had no answer.

R & A stuff is here: http://www.randa.org/en/Rules-and-Amateur-Status/Pace-of-Play.aspx

Naturally all courses will be specific to themselves based on length, difficulty, climate etc etc etc so the course you mention could well have been correct in their 3-ball time

The bit I don't get is the guideline of 20 minutes for an extra player