Miyazato's Driving

The Constructivist wrote recently about Ai Miyazato's chances of rebounding in 2009.  Part of his point was that Ai's injury in mid-2007 robbed her of her fine driving ability and that her Total Driving number from 2006 would have ranked fifth in 2008.  I was curious to see where she and several others actually did rank in 2006 so I went and plugged all the numbers in.  This spreadsheet contains the TD numbers for all qualified players for the last three years.

Total Driving 2006-2008 spreadsheet

Miyazato ranked 19^th in 2006, 133^rd (!) in 2007 and 116^th in 2008.  Much of her problem stems from the loss of ten yards per drive (in '07 she lost 13 yards but gained three back in '08) since her rookie season.  Also significant is the fact that her accuracy rate dropped from .753 to .622 and recovered to only .669.

What originally caught my eye was the fact that Miyazato's actual 2006 ranking wasn't as high as TC and I would have expected.  Upon closer inspection, it seems that almost everybody's Total Driving number was higher in 2006.  The average TD number in 2008 was 68.86 and in 2007 it was 68.64.  In 2006 the average was 70.80, a number which would have ranked 22^nd in 2007.

What caused the Total Driving numbers to decline so sharply after the 2006 season?  The obvious answer - players were not as accurate off the tee in '07 (.654) as they were in '06 (.695).  As a group they averaged 0.7 yards less off the tee, which by itself would have dropped the numbers only slightly.  But even had the average yardage stayed the same, the drop in accuracy would have pushed the TD number down to 69.08.

So even though the Tour lost most of a yard of its average driving distance in 2007, it also failed to hit the fairway nearly as well.  I think we can safely eliminate player discretion from this investigation but what other factors would make players miss the fairway more often?  Poorer weather conditions?  Maybe.  Tougher golf courses?  I think we're getting warmer.  Five events from 2006 did not survive to '07 - Takefuji, Florida's Natural, ShopRite, Wendy's and Franklin Mortgage.  My scoring spreadsheet shows that all five averaged less than 72 strokes per round (the '06 average was 72.929).  Without these five events and with two new tournaments which averaged 74.19 and 73.38, the 2007 scoring average rose 0.386 strokes per round to 73.315.  I have previously noted the scoring difference between 2006 and 2007 and already isolated that difference to the schedule changes.  It stands to reason that the substantial increase in missed fairways was the primary indicator that the courses had become relatively more difficult, and the scoring increase followed along naturally.

This is one reason I built Total Driving the way I did.  By focusing on the raw data instead a player's ranking in the two stats, season-to-season trends like this can be more easily spotted and analyzed.  TD had already helped me dig a little deeper into what makes a golf game tick but this added support to a statement I made nearly a year-and-a-half ago is a nice bonus.