Quote:
Originally Posted by Roger Clemens
I just did a quick calc, it does not mean that much to me but using averages to convey a certainty on how each person should play is not logical.
Strokes gained driving is a derivative stat, no?
And I doubt changing from ranking to deviation from mean changes correlation much.
Strokes gained is a derivative of strokes gained tee to green certainly, but what we are trying to decide is how much more valuable distance is compared to accuracy off the tee. Including the other 2 components of SGTG(approach shots and short game sans putting) is not very effective.
It would be better to isolate the strokes gained driving stat and analyze that. Broadie's book has complete stats from 2003-2012 on the following players
Tiger, Furyk, Donald, Phil, Vijay, Els, Sergio, and Stricker. It also has 09-12 data for Rory.
Here's some results
I ran each players strokes gained driving stat for the year vs their driving distance and accuracy as a % of the tour average.
For example, Luke Donald in 2012 lost
-.06 shots per round off the tee. He was 3.5% shorter than the tour average but 7% more accurate.
What I found was that a 1% increase/decrease in distance was worth +/- .17 shots, while a 1% increase/decrease in accuracy was only worth +/- .04 shots.
As a comparison to Luke above you have Tiger in 2012. He was ~2% less accurate than Luke but he was ~5% longer than Luke.
So you have Luke at -.06.
Tiger was 2% less accurate so subtract (2*.04)
But Tiger was 5% longer so add (5*.17)
=
That gives you a predicted strokes gained for Tiger of .71
What was his actual SG Driving in 2012?
It was .74 strokes gained per round
So 1% driving is +/- .17 shots and 1% accuracy is +/- .04 shots. I looked at a few years of tour data comparing distance to accuracy. What I found there is that generally, a 1% increase in yardage correlated to an almost 2% decrease in accuracy.
Taking this a step further you get every 1% increase in distance is worth .17 but you will generally lose 2% in accuracy which is worth -.08 (2*-.04) for a net gain of .09 shots.
So take the example that I was arguing a few days ago, where a top instructor was advocating he'd rather his student hit it 310 and a bit straighter than 325 and slightly less accurate. Based on the assumptions above that loss in distance represents a 4.8% decrease. Plug that into our equation and you get
-4.8 * .17 for lost distance = -.82
9.6 * .04 for gained accurace = .38
For a total strokes lost per round of .43. Just a wasted half a shot.
Quote:
Originally Posted by Roger Clemens
I picked 3 pros and calculated correlation of their respective stats from this year back to 2006:
a-driving distance rank and strokes gained tee-to-green rank;
b-driving accuracy rank and strokes gained tee-to-green rank.
Bubba Watson: a=-.33, b=.64
Phil Mickelson: a=.28, b=-.29
Luke Donald: a=.62, b=.50
Conclusions from this:
-When Bubba is more accurate, he scores better;
-When Phil is longer, he scores better;
-When Luke is longer or more accurate, he scores better.
I guess somebody could go thru and calculate everybody who's played for at least 5 years.
I don't have any Bubba data but here is some more individualized data for Phil and Luke.
For Phil 1% +/- distance was worth .080 strokes gained driving and 1% +/- accuracy was worth .027 strokes gained driving.
For Luke 1% +/- driving was worth pretty much exactly what the overall sample showed, .17 for distance and .04 for accuracy.
For Tiger the ratios are .12 for distance and .024 for accuracy.
How these individual #s are affected when you are only looking at about 7-10 data points is tough to determine. It's also pretty rare for players to change much especially with regards to distance. So not sure how much signal you can get from individual data.
Quote:
Originally Posted by ntanygd760
I would be curious to see how much better Phil is out of the rough then Bubba.
You would need to know how much better Phil is vs Bubba(/tour) from the rough compared to how much better/worse he is vs Bubba(/tour) to be able to make any conclusion there. If Phil's strokes gained approach from the rough is .2 better than Bubba and his strokes gained approach from the fairway is also .2 better than Bubba it is a wash. PGA Tour has a rough proximity number but it is pretty worthless without distance/strokes gained measurement.
I find it a bit hard to believe that someone's strokes gained from the rough vs the field would be significantly different from their strokes gained from the fairway vs the field at equal distances. Even if there was a statistically significant difference I would then doubt it's big enough to offset what we see above regarding how valuable distance is.
Its hard to go from this.
Strokes gained = SG driving + SG approach + SG short + SG putting
To saying, hey give up some of your SG driving and it will improve your strokes gained overall.
Last edited by NxtWrldChamp; 03-31-2016 at 01:01 AM.