Ratings and Ranking Golfers
Who's the best?
Who's the best golfer in the world? Not such a difficult question. You probably only have to choose between a handful of golfers - Tiger Woods, Vijay Singh, Ernie Els, Retief Goosen and Phil Mickelson. And, on current form, it's probably got to be Woods. You would have a hard job arguing the case for anyone else.
Who are the ten best golfers in the world? That's a bit harder. And, the top 50 golfers in the world? Now it's starting to get really tricky.
If presented with this question, the temptation would be to turn to the Official World Golf Rankings or perhaps the money lists of the European and US Tours. This would obviously give you a fair indication of who are the best golfers in the world, but how reliable are these rankings? Are they really the best way to assess the merits of each golfer? And, if as you discover below, these methods have some fundamental flaws, are there better ways to rate each golfer's abilities?
Official World Golf Rankings
The sports media tend to place great emphasis on the Official World Golf Rankings. In 2004, as Vijay Singh took over the number one spot from Tiger Woods, the sports pages of the world's newspapers devoted many column inches to the story. But did it really mean anything? If you look at how the World Rankings are compiled, you might just decide that it was a silly story that, quite frankly, didn't mean very much.
The World Rankings are compiled using a well-meaning, but ultimately unscientific formula. Points are awarded to players according to the players' finishing position in each professional tournament. The points awarded are generally related to the strength of the field in the tournament. The four majors and the US Tour's Players Championship receive special status because of the strength of competition, and they carry significantly more points. Each players' points are accumulated over a two year rolling period with the points awarded in the past 13 week period doubled. Ranking points decline in eight equal quarter year intervals and after 2 years the points are eliminated altogether.
As World Rankings are based on finishing position, they take absolutely no account of score differentials. So, if a player wins a major six shots clear of the next best player, he will receive exactly the same number of points as if he had only prevailed by a solitary shot. Yet surely, securing victory in a major by a six shot margin should be rated much higher.
Another quirk of the World Rankings is the fact that they assume a minimum of 40 tournaments played in a two-year period. Players who have not participated in 40 tournaments will nevertheless have their points score divided by 40. Although this is understandable in that it prevents players shooting up the rankings by virtue of playing well in a small number of tournaments, it does under-rate players who have been injured or players who choose to play a small number of tournaments. In the unlikely event that a player only played the four majors, but won them all by an average of 5 shots each, the player would retain a lowly ranking as his points total would still be divided by 40. Yet surely he would have to be the best golfer in the world! Although this is an extreme and highly unlikely scenario, it nonetheless demonstrates the peculiarities of the World Rankings system.
The media also made a great fuss of Vijay Singh when he won the 2004 Money List in the US, and cleared $10million in prize money for the season, the first time this have ever been achieved. This was undoubtedly a fine achievement and warranted the plaudits that Vijay received for such a superb season. However, did it make Vijay ten times better than Jeff Sluman who won just $1m in prize money in 2004? And how can we translate this superiority into the number of shots per round?
The manner in which prize money is allocated in each tournament is not proportionate to the number of shots taken to complete the four rounds of golf. For each place up the leader board, a golfer receives an incrementally larger amount of prize money. Thus, the differential between players finishing 60th and 50th, will be much less than between those finishing 1st and 10th. The ability to hold one's game together under pressure is undoubtedly a characteristic that differentiates an average player from a great player, but surely we place too much store on this if we base our opinion on how much money a player has won?
By way of an example, take Craig Parry's victory in the Australian Open at Royal Melborune Golf Club in January 2005. After 72 holes he finished joint leader with Nich O'Hern. Four days play and the pair could not be separated. A play off followed, and Craig Parry eventually triumphed after another four holes. His reward was prize money of Eur225,367, whereas Nick O'Hern walked away with Eur127,708. Twice as good for holding one's nerve? Probably not. Surely the 72 holes of golf was a better guide to the respective merits of each golfer.
Nerve versus consistency
Both World Rankings and Money Lists tend to place greater emphasis on big event performances. They also tend to overrate those finishing in the top few places of a tournament, particular the majors. Arguably, this helps to identify those players with the greatest nerve and the ability to handle the big occasion. Identifying such players is always going to be helpful in picking likely tournament winners, especially the big ones.
However, this does not fairly reflect the 'day-to-day' playing merits of each player. The modern golf professional plays week in week out in regular tournaments, where the key to making a steady living is consistent scoring. To the punter, consistent performance week in week out is equally important. In three ball betting, it's especially important to have such players on your side. You want the best golfer on your side, not necessarily the best one-tournament wonder.
Stroke Averages and Scoring Average
All the major tours calculate stroke averages and scoring averages for players and these statistics do provide a better measure of performance relative to other golfers. However, they both have their flaws, especially the stroke average.
The stroke average is simply defined as the average number of strokes taken per round. The big problem here is that the average takes no account of each course's difficulty and has less value when comparing scores between players who have competed in different tournaments. Therefore, the stroke averages does not take account of the strength of field or the difficulty of the courses played. A player shooting five under par over 72 holes in the Russian Open at Le Meridien Moscow Country Club would apparently rate better than a player shooting four under par over 72 holes in the US Masters at Augusta. Any pundit worth their salt knows that this is not the case, as the Augusta National is a far tougher course. Stroke averages are only relevant when comparing performances on the same schedule of courses.
Scoring averages provide a better guide to a golfer's ability than stroke averages. The scoring average is a weighted average that takes the stroke average of the field into account. It is computed by adding a player's total strokes to an adjustment, and dividing by the total rounds played. The adjustment is computed by determining the stroke average of the field for each round played. This average is subtracted from par to create an adjustment for each round. The net result is generally pretty good in that you find the players that you would expect to see at the top of the ratings.
The scoring average is not perfect though. The main problem with the scoring average is that it fails to take account of the strength of the field. Within the professional ranks, most players are of a very high standard. Yet, there is still a very discernible difference between the journeymen tour golfers and the likes of Tiger Woods. Some tournaments, such as the majors, attract top quality fields, whereas other tournaments attract mediocre fields. The scoring average does not take account of this. It assumes that all tournaments attract fields of the same quality. The better golfers play in the better tournaments against better competitors, yet they receive no beneficial adjustments to their scoring averages. The net effect of this is that the scoring average tends to narrow the differential between the best and worst golfers.
So where does that leave us? Is it possible to take account of the strength of the competition?
Fully adjusted scoring average
Well, the answer is yes. For those betting on golf, it really pays to look at a 'fully adjusted scoring average'. It sounds a bit of a mouthful, but essentially it means ratings based on actual scores, adjusted for the difficulty of the course and the relative strength of the other competitors in the tournament. The system used is very similar to the way in which handicappers rate performances in horse racing. Indeed, this handicapping type of system is probably even more relevant to golf than it is to horseracing, since the size of field in a tournament is so much larger. With over 150 players competing in most tournaments, it becomes a statistically reliable exercise to assess the relative strength of the field and work out the best fitting ratings to the result.
The ratings presented on www. progolfform. com are fully adjusted scoring average ratings. They work by calculating an 18 hole scoring average for the tournament and then adjust them for the relative strength of the field and for the course conditions. For example, in the 2005 US Masters at Augusta, Tiger Woods had a stroke average of 69 for his four rounds. An adjustment was then made to this rating of -3.50, reflecting the relative strength of the field and the difficulty of the course. The adjusted rating of Tiger Woods was therefore 65.50. The same adjustment is applied to all scoring averages of the players competing the same four rounds in the tournament.
The system throws up results largely as we would expect them. Tiger Woods, Vijay Singh and Ernie Els all figure as the top players under this system. They all consistently record low ratings. The ratings don't, however, overestimate one off performances, as a one-off low rating can be set in the context of a string of otherwise weaker performance ratings. Furthermore, a wide margin winner will be given due prominence and a small margin victory won't be over-rated.
For the bread and butter, mid-ranked golf professional, differentiated ratings undoubtedly offer the best guide to their relative merits. They offer the serious punter with a reliable performance guide. The predicted score of players can be compared with others, and direct and quantifiable comparisons can be made.
The ratings also facilitate direct comparisons between golfers playing on different tours. In the modern game, there are enough golfers playing on both the US and European Tours to help tie in the form on either side of the Atlantic. Therefore, reliable comparisons can be made between the level of form shown by a golfer playing on the European Tour and a golfer playing on the US Tour.
But if only it were that easy
Other factors are, of course, still at play in assessing the chances of a golfer in a particular tournament. For example, a player may be out of form. Certain courses and playing conditions will suit certain golfers. Similarly, the fitness and mental well being of a golfer will affect his immediate performance. And then there's luck!
Multiple factors are at work when a player enters a golf tournament, and it is extremely tough work trying to assess their chances. Nonetheless, ratings provide a good starting point for making judgements of likely performance. The fully adjusted scoring average provides by far the best starting point available, better than world rankings, money lists, stroke averages and even scoring averages.