1. Roland Minton Roanoke College Golf by the Numbers, JHU Press
Data Mining Cave-Ins
Roland Minton
Roanoke College
Golf by the Numbers, JHU Press

2. System of volunteers and lasers
1.2 million shots (20,000 rounds) per year, 2004-present
PGA Tour events only

3. 15, 3,03,155,01,S,TeeBox,,Green, {R,PGATOUR,2008,380,01035,745,027,
Tommy,Armour III,01,The Barclays,Ridgewood Country Club,
15, 3,03,155,01,S,TeeBox,,Green,
Unknown,05171,05400,N,N,,
,0907,Good,With,Level, 9, , 8, , ,00022,00000}

4. Where Did the Ball Stop? It started 5171 inches away.
It traveled 5400 inches.
It ended 228 inches away.
The ball went too far (long).
The ball was not on line.

5. Where Did the Ball Stop?

6. Where Did the Ball Stop?

7. Where Did the Ball Stop?

8. Da Secret Code It actually is the result of rounding.
When I “unrounded” the data,

9. Da Secret Code
The inner branch is approximately

10. Da Secret Code If B changes to B – 1 and x = 0,
Assume that B, d about the same,
and convert to feet.

11. Coming Up Short
Means of y-values

12. Different Strokes
Std deviations of y-values

13. Going Offline
Std. Dev. of |x|-values
Means of |x|-values

14. Correlations Sort the data by tournament.
Correlate percentage of putts made from a given distance and score.
The first time I did this I got

15. Correlations From 0-3 feet, -.150 From 3-4 feet, -.104

16. Correlations
From feet, the scatter plot is

17. Correlations
When only those who made the cut were included in the calculation,
From feet,
From feet,
From feet,
What does this mean?

18. Correlations

19. Lake Wobegon Open Ranking system for bunker (sand) play:
For given player, for each bunker shot
Compare “score” to “average score”.
Add up all differences and divide by total number of bunker shots.

20. Lake Wobegon Open Compare “score” to “average score”.
Distance before B, distance after A
Replace A with tour avg. # putts from A
Find tour avg. distance after from B
Replace with tour avg. # putts
Difference is value of shot.

21. Lake Wobegon Open Ranking of tour players looks right.
In 2008, #1 Mike Weir 0.147
The sum of all the ratings is
(These guys are good!)
So A – A > 0 !

22. Lake Wobegon Open Two problems with averaging.
1) The function avgputts(d) is not linear
but is concave down.
So 5 feet better beats 5 feet worse.

23. Lake Wobegon Open Two problems with averaging.
2) “All” is not the same as “all.”
The tour average is ALL shots, but I only computed ratings for the most active 230 players.
For this type of shot, the regular players are better than the irregulars.

24. Any Questions?