Wednesday, June 4, 2014

Why You Win or Lose in Team Play

Team play pits golfers from one club against another club.  Historically, clubs would choose their best players to go against the opposing club in a gross score competition.  The winner would have bragging rights for a year.  For a variety of reasons, team play in the United States has evolved largely into a net score competition.   There are four reasons a club will win such a team competition: 1) Errors in Course and Slope Ratings, 2) Favorable handicap allowances, 3) Handicap management practices, and 4) Chance.  In essence, winning is either caused by having an unfair advantage or luck.   Let’s review each reason to emphasize why winning is not a basis for bragging.

1) Errors in Course and Slope Ratings - Previous posts have explored the size of the errors in Course and Slope Ratings.[1]  Such errors make little difference in intra-club events.  Errors can have a substantial effect, however, on inter-club matches.  Table 1 presents various course statistics for five clubs that participate in team play in Central Oregon.  Looking at the statistics, it appears the five courses are approximately equal in difficulty for the scratch and bogey golfer.  Most golfers interviewed, however, believe Tetherow is the much tougher course.  Tetherow has undulating greens, blind shots and hazards, and is extremely penal to off-fairway shots.  These difficulties are not reflected in the obstacle values estimated for the course by the Oregon Golf Association (See Table 2). [2]   The scratch obstacle values for the five courses are approximately the same.  The bogey obstacle value at Tetherow is below the average of the other four courses.

Table 1
Course Statistics

Course
Yardage
Course Rating
Slope Rating
Bogey Rating
Broken Top (Green)
6559
70.7
133
95.4
Bend (Blue)
6557
70.9
130
95.1
Awbrey Glen (Gold)
6572
71.0
127
94.6
Tetherow (Tan)
6495
70.7
128
94.5
Crosswater (Tournament)
6550
71.1
135
96.2

Table 2
Obstacle Values

Course
Scratch Obstacle Value
Bogey Obstacle Value
Broken Top (Green)
0.0
3.7
Bend (Blue)
0.2
3.4
Awbrey Glen (Gold)
0.2
2.8
Tetherow (Tan)
0.3
3.2
Crosswater (Tournament)
0.4
4.6

There are methods for estimating the errors in Course Ratings.[3]  Golf associations are hesitant to study the problem because they lack the expertise and it is not in their interest to challenge the accuracy of the Ratings.  Without the requisite data, a range of errors is assumed and the resulting impact on matches is evaluated.  For simplicity, it is assumed the scores of each player are normally distributed with a  standard deviation of three strokes (i.e., 68 percent of all scores will be between plus and minus three strokes of the player’s average score).  From these assumptions, the probability that the player with the advantage (i.e., his Course and Slope Ratings are below the true Ratings) will have a lower score than his opponent can be estimated.  The results are presented in Table 3.[4]  The probabilities of winning are for a stroke play event.  This is an adequate if not an exact proxy for winning a match play event. 

Table 3
Probability of Winning with Various Errors in Handicap
               
Error in Handicap
Probability of Winning
0.0
0.50
0.5
0.55
1.0
0.59
1.5
0.64
2.0
0.68
2.5
0.72
3.0
0.76

 Table 3 shows that a player with a 2-stroke advantage has a 68 percent chance of winning.  A 2-stroke error in handicap is not out of the realm of reason, especially for the higher-handicap player.  Assume Tetherow had the same rating as the Nicklaus Course at Pronghorn (Rust Tees).  The Nicklaus Course and Tetherow are considered equally difficult by many players.  If anything Tetherow is more difficult for the bogey golfer.  The Rust Tees have a length of 6533 yards, a Course Rating of 71.3, and a Slope Rating of 143.  Applying these new Ratings at Tetherow, a 10-index player becomes an 8.5-index.  So when the Tetherow player goes to Bend, he would now play as a 10-handicap rather than a 12-handicap under the current Ratings.

A typical team event consists of 10 single matches and 5 four-ball matches.  If there was a 2-stroke error in handicaps, the team benefiting should win 6.8 of the 10 singles matches on average.   In the four-ball matches, where both players have a two-stroke advantage, the team benefiting from the errors should do even better.

2) Handicap Allowances – In some team competitions, the handicap allowance is a percentage of a player’s index.  In the case of Central Oregon, the percentage is 80 percent. This gives the team with more low-handicap players an edge.  For example, assume a 10.0 index was to play and 8.0 index on a course with a Slope Rating of 130.  The 10.0 index player would receive three strokes in the match if it was played at full handicap.  If the 80 percent allowance is applied, the 10-index player only receives two strokes.  As shown in Table 3, this decreases his chance of winning by 9 percent.  A team composed of lower-handicap players than its opponent should have a decided edge.

3) Handicap Management Practices – There will always be some players who increase their handicap over what it should be.  There has been a case (not in Central Oregon) where a team chose to forfeit a match rather than play against a notorious sandbagger.  There are unethical players who are scorned in club tournaments, but welcomed to compete for the club’s team.   Having one or more sandbaggers on the team increases the probability of winning while at the same time decreasing the reputation of the club.

4) Chance – Chance is omnipresent in golf.  The poor shot that skitters on to the green or the great shot that is hit with a gust of wind and ends up in a hazard are examples of chance at work.  But winning because of chance should not be cause for pride.  After all, if you called heads, and the flip came up heads you would not attribute your win to any superior physical or character trait.

In summary, there is no reason to take great pride in winning a team match.  The winner either had an unfair advantage or was lucky.  In theory, team matches should not be about winning, but making friends with players from other clubs, enjoying the competition, and learning how to win and lose with grace.  History will little note nor long remember who won a team competition.   Emphasis on winning, rather on the social aspects of team competition, diminishes the benefits of participation.   

  






[1] Dougharty, Laurence, “Empirically Verifying Course and Slope Ratings,” www.ongolfhandicaps.com., April 18, 2013.
[2] To calculate the obstacle values, it was assumed that the Course Yardage was also the “effective” yardage.
[3] A promising method is being developed by Peter Preston.  Preston uses away scores to estimate the actual Course Rating.  These estimates can be compared with the official Course Rating to determine if significant differences exist.  See Preston, Peter, “Estimation of Golf Course Ratings from Player Scores,” paper presented at  59th ISI World Statistics Congress, Hong Kong, August 2013.
[4] The methodology behind these estimates is shown in Dougharty, Laurence, “A Sandbagger’s Guide to Winning,” www.ongolfhandicaps.com, December 19, 2013.

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