Dramatic Slope Change At Pumpkin Ridge - Witch Hollow

[John Kirk]

The USGA re-rated both courses at Pumpkin Ridge Golf Club (North Plains, OR) this year.  There is a dramatic change in slope for the blue tees (about 6500 yards) at Witch Hollow.  The most recent rating/slope had been 72.7/142, which I thought was a touch high.  Here are the new men's ratings for both courses:
                               Witch           Ghost
WHITE TEES            69.8/134       69.2/131
BLUE TEES              72.4/131       72.1/138
BLACK TEES            74.7/139       74.0/145

A.  How does an unmodified course's slope drop 11 points?  The assistant pro talked to a USGA (or was it OGA) representative, who explained that the slope is calculated on a variety of factors, which include the average green speeds and rough length, plus the distance and severity of hazards from the tee.

B.  Why is the slope lower from the blue tees?  I've never seen this before.

C. Ghost Creek is considerably easier than Witch Hollow from the blue tees.  It's much more wide open, and the back nine is easy.

To offer some statistical evidence, I took a copy of the results from this year's club championship.  We play Witch Hollow from the blues on Friday.  On Saturday we play Ghost Creek from the blues (there were actually 4-5 black tee boxes used, including #8, a 70 yard difference).  On Sunday we play Witch Hollow from all the way back, a very difficult test.

I would estimate the average handicap index of the contestants at 3.0-4.0.  34 players finished on Friday and Saturday; only 28 played on Sunday.

                             Friday    Saturday    Sunday
AVERAGE SCORE    80.44       77.85        83.93
STD DEVIATION        6.10         4.56          6.15

This is fairly typical of each year's results.  Ghost Creek is always 2-3 strokes easier.  I included the standard deviation because, without proving it here, I think it correlates positively to course slope.

Once again, without taking the time to reacquaint myself with statistical analysis, I think there is a large enough sample size to say with high confidence that the difference (Witch 72.4, Ghost 72.1) in course rating is too small, and that Witch Hollow's slope should be higher.

How can the raters make such a large error?


 

[JohnV]

OGA, not USGA.  The USGA does not rate courses.

A.  Yes, if the greens are now being kept slower and the rough cut lower it would cut the numbers, but I'm surprised to see it cut them that much without changing the course rating a lot.

B. It is unusual to have the slope be lower from longer tees but it can happen.  You have to realize that the slope just represents the "slope" of the line between the Scratch Course Rating and the Bogey Course Rating.  By reversing the calculations I can tell you that according to these ratings the Bogey golfer would shoot 96.75 from the blues and 94.7 from the whites.  Notice that the difference is less than the difference between the course ratings (2.05 vs 2.6) which is why the slope is less from the blues.  What that says is that the course plays a lot easier for the scratch player from the whites, while it is still pretty hard for the bogey player.

C.  The Course Rating for Witch is higher than for Ghost.  The guys who play in the Club Championship are a lot closer to scratch golfers than bogey golfers so that is the relevant number, not the slope.

I can't say if it is an error or not, but if the club has a problem with it, they should appeal to the OGA.  That change seems very dramatic to me also and I think the club should appeal just so that the OGA will go through the process of looking at why it changed.

[Mike Nuzzo]

If the "Obstacles" are closer to the bogey players landing area when playing from the white vs. blue tees the slope could be higer.

The assumption when rating a course is that the bogey player hits it 200? yards from the tee.

So if 200 yards out from the Blue tees is 40 yards of fairway vs. 30 yards of fairway from the white tees the obstical factor from the white tees would be higher.

Generally you try to make it easier for the players playing from the more forward tees.  Yes it does sound strange.

If there is no fairway from a few white tees, 200 yards out, and they are forced to lay up, and then have no ability to reach the green (the bogey player hits it 170 on their 2nd shots) then you could wind up with some awkward situations that increase the slope.

There are 10 obstacle factors when rating a course.

Cheers