A Question on Course Rating and Elevation

[bkuehn1952]

Someone was complaining that his index was developed playing at elevations such as 4,500 feet. He felt that while he can drive the ball 275-280 yards at his elevated course, his index is too low when he plays at sea level and can only hit a drive 255 yards.

All things being equal (6,500 yard course, 130 slope), wouldn’t the course rating reflect the difference a scratch golfer can hit driver and other clubs? A mile high course might be 70.2 versus a sea level course with 71.4?
 

A few of you are involved in course rating. What do you know?

 

[iacas]

The elevation is absolutely considered in the course rating. It affects how far you hit the ball, and those numbers are adjusted.

CommonGround in Colorado (Hi @DeadMan!) is 7229 from the back tees and rates out at 73.0/131 and Whispering Woods (the one in Erie, PA, not where I am currently in NC) rates out at 74.0/145 from 6804.

Why? The effective playing lengths of the holes.

(The whites are 6365/68.9/119 in Colorado and 6052/70.3/137 in Erie. Higher in Erie despite being 313 yards shorter.)

[DeadMan]

Yeah, as an example, TPC Colorado is the longest course around here. It’s hair under 8000 yards and rated 77.2/138. French Lick in Indiana is 8100 yards and rated 80.0/148. To have your course rating be around par here, you need to be 6500+ yards. 
 

There are other differences from playing at elevation - the ball also spins less, as an example. The transition between elevation and non elevation can take some time to get used to, but I don’t think your handicap would change. 

Edited April 2 by DeadMan

[iacas]

11 minutes ago, DeadMan said:

There are other differences from playing at elevation - the ball also spins less, as an example.

I hope you mean "when it lands, because it spent extra time in the air," because otherwise… I'm gonna go find Bill Nye or Professor Proton or something. 😄 

[DeadMan]

1 hour ago, iacas said:

I hope you mean "when it lands, because it spent extra time in the air," because otherwise… I'm gonna go find Bill Nye or Professor Proton or something. 😄 

Well, I legitimately thought it spun less, but now that I’ve looked it up, it’s really just the effect of less air density on the ball. So the ball flies lower and won’t hook or slice as much.

[iacas]

8 hours ago, DeadMan said:

Well, I legitimately thought it spun less, but now that I’ve looked it up, it’s really just the effect of less air density on the ball. So the ball flies lower and won’t hook or slice as much.

Oh, yeah. I thought you meant how it spun on the green.

But, yeah, the air density doesn't have anything to do with the impact physics. 😉 

[bkuehn1952]

Thank you, guys. Exactly what I wanted to know and the examples were spot on.

[arturo28mx]

I play in Mexico City at 7,000 ft elevation. Air is thinner, so you have two effects: less drag and less lift. Ball flies longer but lower.

Same effect on clay birds when shooting sporting clays. Discs fly longer and flatter.

Spin is not dictated by elevation. It is dictated by swing speed and loft.