Stoney Hill Challenge (April 9-10, 2011)

I was TD of this event, and a player has noted an odd result in the ratings. In rounds 3 & 4, the same score by players in the Intermediate division resulted in a rating 26 points lower than other divisions (in the unofficial ratings).

The Intermediates played a slightly different layout---a shorter tee on 1 hole, and only about 50' shorter on a 608' hole (to reduce a water carry). It's hard to believe this small change would make that much difference.

I've looked and don't see any glaring errors on the score entries though, knowing my capacity for errors, someone might yet point one out.

Could this be an artifact of a small number of propagators? Only 8 rated players on that layout, 1 of which is surely outside the range to be used.

Or does this occur often where different divisions use different layouts, and I've just never noticed?

Statistically, 95% of the time the SSA variance from round to round under the same conditions is 3.9 for 10 props on a 50 SSA course and 2.8 on a 43 SSA course. So that's within normal variances expected for only that many props. That's why we combine rounds for official ratings when possible. For comparison, with 30 props, the variance drops to 2.3 and 1.6 respectively for those same 50 and 43 SSA courses and 1.3 and 0.9 for 90 props.

Thanks, Chuck.

I don't actually understand all that, but thanks.

I'll just interpolate that 7 propagators on an SSA 58 course creates an even greater variance, and place the blame there.

The SSA with just 7 props on an SSA 58 course could vary up to 5 shots from round to round under the same conditions.