Tuesday, September 05, 2006

Player Rating System

In my most recent player rankings post (August 21), I mentioned a point system I devised to rate the players. I thought I’d go into some detail about how that system works.

First, I decided that I didn’t care to rate ALL of the players – just the top forty or so. Second, I wanted a system that would make it simple to collect the data and calculate for a group of 50-60 players. Third, I wanted a method that I could use to go back and rate players from previous seasons.

I settled on a combination of five statistical categories, all of which can be found at LPGA.com – scoring average, money earned, victories, Top 10 percentage and missed cuts. In each of these categories, the player earns points based on their performance. 25 points are allocated for scoring average, 25 points for money, 20 points for victories, and 15 points apiece for Top 10 percentage and missed cuts. If a player maxes out the chart in all five categories, her score is 100. At this writing, Lorena Ochoa scores at 93 for the 2006 season because she’s #1 on the money list (25 points), averages 69.52 per round (24 points), has won three times (15 points), has finished Top 10 73% of the time (14 points), and has not missed any cuts (15 points).

Scoring 100 can be done if you earn the most money, average under 69 per round, win four tournaments (or three with one major, or two majors), finish in the Top 10 in 90% of your starts, and make every cut. In looking back over the last few years, not even Annika Sorenstam has managed to score 100 by this method. But she’s cranked out a nice string of 98s. At first glance I believed I would have to tweak the scoring average scale as I went back to rate players from the 70s or earlier. But I then realized that the object of the system is to rate the players within the same time frame (season), then the rankings that result could be used to compare players across eras. More important to keep the formula static and simple. I’m working on past seasons and will start posting the results very soon.

Here are the Top 30 players of 2006 as ranked by my system through the State Farm Classic:
1. Lorena Ochoa 93
2t Karrie Webb 91
2t Annika Sorenstam 91
4. Cristie Kerr 82
5t Juli Inkster 75
5t Mi Hyun Kim 75
7. Jeong Jang 67
8. Hee-Won Han 65
9t Michelle Wie 63
9t Seon Hwa Lee 63
11. Paula Creamer 61
12. Se Ri Pak 56
13. Pat Hurst 55
14. Natalie Gulbis 50
15. Brittany Lincicome 47
16. Shi Hyun Ahn 43
17. Sherri Steinhauer 42
18. Jee Young Lee 40
19. Meena Lee 38
20. Ai Miyazato 37
21. Morgan Pressel 35
22t Stacy Prammanasudh 34
22t Sophie Gustafson 34
22t Young Kim 34
25. Brittany Lang 29
26t Julieta Granada 28
26t Beth Daniel 28
26t Wendy Ward 28
29. Angela Stanford 27
30. Gloria Park 26

I haven’t set this system in stone yet. I’m not convinced I have enough points allocated for Victories, and I don’t know that the sliding scales for Money and Missed Cuts are exactly right. I do know that the list looks reasonable – for example I would have subjectively put Cristie Kerr at #4, and would have put Michelle Wie and Paula Creamer around the 10th spot since they have not won this year but their other stats look very good – so that leads me to believe that the system “works”.

My “official” rankings will still be the posts I designate as “Top 20”, because I reserve the right to subjectively rank the players (it’s my list and I’ll make it the way I want!). This point system is a starting place from which I’ll tweak the positions as I see fit.

1 comment:

svenson said...

I'm intrigued by your rating system. If the top money winner gets 25 points, does the second wealthiest get 24 and so on for all categories?