Golf Stats Redux

[A.G._Crockett]

Some weeks ago, we had a thread about the possibility that golf stats are not revealing as much about the game as they might.  Bill James' work in baseball was cited as a paradigm shift, which I wholeheartedly agree with.

Consider this from the latest issue of Golf World:
     The Tour leader in all-around stats for 2004 was Geoff Ogilvy!  Ta-da...

Ogilvy topped Singh 268-282 by adding rankings in nine statistical categories (like the game itself, low score wins!).  He was 2nd in eagles per hole, fourth in sand saves, and 7th in driving distance.  However, Ogilvy was 49th in money in 26 events.

Singh, on the other hand, won the Vardon Trophy at 68.84, despite finishing second overall in the stats.

So, the question remains:  Is the game a bottom-line, get it in the hole deal in which stats can never tell the whole story, or do the stats need a revamp to give a more accurate picture of WHY Singh was able to get it in the hole more quickly more often than anybody else in the world?  (Or is that two questions?)

[Doug Siebert]

Stats rarely measure the right things in any sport (or like baseball, measure so many you can prove almost anything you wish if you dig deep enough)  Putts per round is a great example of a mostly useless stat.  Sand saves is neat, but it is so narrow because pros just aren't in bunkers that often so the difference between 10 and 100 doesn't amount to a stroke's difference during a whole tournament.  Driving accuracy is a nice stat, but for the missed fairways, how bad they are missed is what is important.  I have my own stat to determine how well I drove during a round, which is "number of drives that left me in tree trouble".  Betcha Tiger is near the bottom in that this season

Though my current favorite is the "time of possession" stat for US football.  Why oh why don't they realize they should discuss "number of offensive plays" which would be a 1000% better stat for the purposes "time of possession" is used for by commentators.

[Kelly Blake Moran]

Doug,

I probably have the specifics not quite right, but as I recall in the mid-70's in a big matchup of highly ranked teams, Texas vs Texas A&M,  the Longhorns kicked off to open the game A&M fumbled and Texas ran it in for a touchdown.  The next kickoff A&M handled.  They ran a pitch out on the first play and Texas intercepted and ran in for a TD.  Offensive plays run:  A&M 1  UT 0   Score: A&M 0   UT 14;  Time off the Clock: about 50 seconds.  

[Brent Hutto]

Singh, on the other hand, won the Vardon Trophy at 68.84, despite finishing second overall in the stats.

So, the question remains:  Is the game a bottom-line, get it in the hole deal in which stats can never tell the whole story, or do the stats need a revamp to give a more accurate picture of WHY Singh was able to get it in the hole more quickly more often than anybody else in the world?  (Or is that two questions?)

The answer is that an awful lot about the game can be understood by looking at it statistically. You'll never completely reduce golf to a formula but you could learn a lot by looking at the proper measures. The bad news is, the useful numbers are not published. Of the "stats" traditionally quoted by the media the only one that's of any real value is probably Greens in Regulation. The others are probably useful to a player but are absolutely no good at all for understanding what leads to success on Tour.

Here's what I mean by that. Let's say it's the end of the season and a player suspects that he needs to work on his sand game. His percentage of sand saves relative to his peers might help him decide whether that's really true. Obviously if he looks at the stats and sees he was the fifth-best player on Tour in sand saves that might lead him to go spend his off-season practice time on something other than bunker shots. But as an outsider trying to estimate the importance of sand play to success on the Tour, sand saves as an isolated measure is useless because the context in which that little part of the game occurs is poorly understood and yet the context is many times more important than sand play per se.

Let's start by looking where the light is brightest. The most simplistic reduction of the game of golf would be to say "Well, there's putting and then there's everything else". That's a pretty defensible starting point IMO because it is possible to be a good or bad putter somewhat independently of ball striking. OTOH, if you're great with the driver you're not likely to be really terrible with irons or wedges or vice versa (although you may be relatively worse with one kind of shot than another there's still more overlap between different kinds of ball-striking ability than between ball striking and putting). So if he had a good measure of how well someone putts and a good measure of how well someone strikes the ball we ought to be able to figure out something about the game of golf, no?

Starting with putting, what we ideally want to know is three things for each putt: 1) how long was it, 2) what break and slope did it have and 3) was it the first putt vs. a second or third putt. These factors together along with some minor factors like green speed and smoothness, wind and type of grass (these are minor only because they tend to be very similar among all putts in a round and also they tend to be the same for a large number of players in any tournament so they average out well) determine the difficulty of each putt. Knowing the difficulty and knowing whether the player missed or made the putt enables us to compute various statistics that measure putting ability. None of these factors are recorded in Putts per Round or Putts per GIR which is why I say those stats are useless. I'd argue that the length of each putt is by far the strongest indicator of its difficulty (note, there is a complicated argument I don't have time to explain as to why I make this assumption but it has to do with the non-random component of distance being more strongly dependent on ball-striking than the non-random component of slope and difficulty once you average over enough different situations) so we could probably build a good model of putting from knowing only length and whether it was a first putt. This information is available from ShotLink but not published in any usable (i.e. raw) form.

Once we figure out a little bit about putting we need a measure of ball-striking success. On average, the task for a Tour player is simple. Get as close to the hole as possible in regulation strokes and when possible get close to the hole in one less than regulation strokes. In other words, we can assume a demarcation line between putting and ball striking to exist after regulation strokes with an exception for reachable Par 5 greens and drivable Par 4 greens. When the player hits the green in regulation strokes, then the combination of our ball striking and putting measures will have pretty fully accounted for the outcome. When he misses the green there will be one or more short-game or recovery strokes. While a complete golf-success model would require accounting for differences in ability on those in-between shots I'd argue that we can learn enough from the first two components to just ignore the short game until we've nailed down putting and ball striking.

Here's why I say GIR is actually the one useful stat in the tradtional list. There have been models attempted using the traditional stats and the usual finding is that when comparing Tour players to each other or when comparing amateurs or various levels of ability GIR always comes out as a significant predictor of scoring and is often the only significant predictor (when the other stats are in the model at the same time). So obviously there's some value there. Since hitting the ball close to the hole is of great importance and since on average a ball on the green in regulation strokes is closer to the hole than one that misses the green (note that's on average, not in every single case) then the significance of plain old GIR tells me two things. One is that GIR is at least a decent approximation to "how close to the hole" and the other is that "how close to the hole" must be really important if a weak measure like GIR has considerable predictive power.

To improve on GIR you need to know an actual distance and you need to distinguish between balls on the green versus balls in the fringe versus balls in the rough versus balls in the sand and so forth. Once again, ShotLink has that data but it is not generally available. I'd say for a first model of golf success you could start with just the putt-by-putt distance and made/miss records I mentioned along with a list of how close to the hole the ball was after regulation strokes and whether it was on  the green or not. Just like I'm suggesting that we disregard variation in short-game ability for our first model I would treat all balls that miss the green in regulation the same in the interest of simplicity (because once you account for where off the green the ball ended up then you really, really need to account for the short-game shots that advanced it from there).

So here's my thesis. Go get ShotLink data for where the ball was in regulation strokes (plus optionally where it was in one less than regulation on drivable Par 5's) as well as the distance for each putt made or missed. With that data you will be able to do two things: 1) you can characterise the degree to which putting ability varies among Tour players and how that variation impact succes and 2) you can characterise the variability in ball-striking ability among Tour players and its effect on success. You'll also be able to assess the degree to which those are truly separate versus the possibility that good putting and good ball striking are in fact occuring in the same players.

[Mike_Young]

IMHO what the leading money winners all have in common...no matter what the stats confirm is that somehow they get their regulation approaches close to the hole more than the rest of the field.  

[A.G._Crockett]

Brent,
Two questions for you:

1. What do you do for a living?  If it ain't in statistics, you are wasting a real talent!

2. Any chance you can come over and help my son write up his 8th grade Science Fair project on the effects of corking a baseball bat?  Reading your stuff, I realize I'm WAAAY over my head!  

[Brent Hutto]

1. What do you do for a living?  If it ain't in statistics, you are wasting a real talent!

Yes, I'm fortunate to get paid for something I'm actually interested in. In fact my specialty, to the extent that I have one, is measurement. It can get really fascinating to figure out what it is someone really wants to do with a statistical model and then figure out a "good enough" way to measure it when they can't get perfectly-observed information.

2. Any chance you can come over and help my son write up his 8th grade Science Fair project on the effects of corking a baseball bat?  Reading your stuff, I realize I'm WAAAY over my head!  

If he has some data we can certainly come up with a convincing way to present it.

[Doug Siebert]

Brent,

One minor nit to pick in your post.  I don't agree that good driving and good iron play are necessarily overlapping.  The goal when driving is to hit it as far as possible while still maintaining control.  The the pros individually do it to varying degrees of success.  But even if you striped every ball 300+ and in the fairway that might not correlate to success in iron play on tour, because distance control is out of the equation, and that's becoming a more and more important part of success on tour.

Watch the guys who are hot and even when they miss directionally they are amazingly close distance wise.  Most of us mortals only worry about distance control with wedges, and only to a gross approximation with the rest -- hitting a "hard 8" or a "soft 6" when you are in between clubs.  An 8 iron's an 8 iron to me, I don't hit it differently when I'm 162 yards versus 164 yards, but the pros apparently do.

The stats for sand saves, and short game in general, are colored so much by putting that I agree with your postulation that its down to putting and GIR, and everything else is secondary and much harder to quantify.  Better putting has a beneficial effect on the rest of the game all the way up.  When I'm putting really well, I hit closer to the hole on short game shots because I don't feel pressured to get it within 3-4 feet to save par, I still feel pretty sure I can make it if I'm 8-10 feet away so I'm making a more confident stroke and more willing to take chances.  And my approaches are therefore easier, because I don't feel like a missed green is going to lead to a bogey, or feel like I need to knock the flag down to make birdie.  How can you capture that with statistics?

[Brent Hutto]

One minor nit to pick in your post.  I don't agree that good driving and good iron play are necessarily overlapping.  The goal when driving is to hit it as far as possible while still maintaining control.  The the pros individually do it to varying degrees of success.  But even if you striped every ball 300+ and in the fairway that might not correlate to success in iron play on tour, because distance control is out of the equation, and that's becoming a more and more important part of success on tour.

The traditional stats don't shed much light on this subject but you make a good point about the goals of driving and iron play being quite different (perhaps with the exceptions of courses that are very short/tight or "strategic" off the tee). Getting as much distance as possible without putting the ball in jail versus getting an exact distance with the best directional control possible should show up as separate skills to some extent. Of course if you do a good job of measuring how far from the hole the ball ends up in regulation strokes that will be a good composite of both kinds of ball striking so you can do that analysis first and then model driving and approach shots separately as factors sort of nested within the ball-striking model.

The stats for sand saves, and short game in general, are colored so much by putting that I agree with your postulation that its down to putting and GIR, and everything else is secondary and much harder to quantify.  Better putting has a beneficial effect on the rest of the game all the way up.  When I'm putting really well, I hit closer to the hole on short game shots because I don't feel pressured to get it within 3-4 feet to save par, I still feel pretty sure I can make it if I'm 8-10 feet away so I'm making a more confident stroke and more willing to take chances.  And my approaches are therefore easier, because I don't feel like a missed green is going to lead to a bogey, or feel like I need to knock the flag down to make birdie.  How can you capture that with statistics?

Well, there are all sorts of problems inherent in measuring confidence or other psychological traits or states of mind. Quite likely that will remain out of reach of any practical statistical analysis.

However, there is an approach that does lend itself to separating putting from the short-game shots (as well as having some promise for separating driving and approach shots). If you know the distance from the hole after each stroke then you examine the success or failure of short-game shots based on how far they end up from the hole and then you separately look at putting from whatever distance the first putt ended up being. In other words, if you consider any bunker shot followed by a made putt to be a "success" and any bunker shot followed by a missed putt to be a "failure" then the thing you're measuring is really "bunker shots followed by a putt" which is as much putting skill as sand play. Better to consider shades of gray in sand-play success by rating each shot based on how close to the hole it ended up. For instance, over the course of a season you might find that Tour players on average hit shots from greenside bunkers within five feet 30% of the time, within ten feet 70% of the time, within twenty feet 95% of the time and they hole out one bunker shot in twenty. So a particular shot that ends up eight feet from the hole isn't all that great by Tour standards (note that I just purely made up those numbers for discussion) but if a player hits four bunker shots in a round and they end up two feet, four feet, five feet and ten feet then he's had a great bunker-play round even if he only made two of the four putts (which would be 50% sand saves in the traditional stats, no great shakes).

[Brent Hutto]

Continuing for a moment with the approach I was describing in my last reply...

There's a guy named Doug Massey who used to post to the rec.sport.golf newsgroup and he came up with an approach to evaluating a player's results in different facets of the game with "strokes" as the metric. Specifically, he attempted to create a table which showed the "expected number of strokes" to hole out from any given situation for some particular skill level of player (scratch, Tour pro, etc.) so for example for a scratch player the "expected strokes" putting from six feet might be 1.5 meaning that on average scratch players make the putt (one stroke) half the time and get down in two (two strokes) half the time. In this case, the word "expected" is in the math-stat sense meaning something akin to "on average".

Using the ShotLink data it should be possible to compile this table for Tour players. So the expected strokes for 187 yards in the fairway might be 2.8 meaning that they make birdie (down in two strokes) slightly more often than they make bogey (down in four strokes) but most often get down in three strokes for par. For a 25-yard greenside bunker shot it might be 2.4 which would indicate some combination of holing out, getting up and down and getting down in three or more strokes with the average being closer to two than three strokes.

Such a table would directly show the value of distance versus hitting fairways. You might find that all of the following shots take Tour players 2.8 strokes on average to get in the hole:

a 190-yard approach from the fairway,
a 180-yard approach from the first cut,
a 165-yard approach from a fairway bunker,
a 155-yard approach from the real rough and
a 110-yard approach from the trees

As long as the Tour-average number of strokes to get the ball in the hole are equal for all these, you can treat those distance as the de facto tradeoff between how far the drive goes and where it ends up. In terms of actually implementing a system like this, it depends on how many categories of "where the drive ends up" are recorded in your raw data. Obviously, no real-world system will capture "the ball is sitting in a down lie in dormant two-inch Bermuda with the grain against the shot" but hopefully you'd at least get the basics like fairway, first cut, heavy rough, bunkered, in the trees, out of bounds, etc.

Once you have a table of expected-strokes it is possible to evaluate a player's round or season in any desired portion of the game. You can use the actual scoring average for each hole as the starting value and at the end of a round all of a player's shots will end up pretty close to summing to his score relative to the field's scoring average for that round. However, the more interesting usage is for an individual player to see how parts of his game are contributing to his scoring over a whole season (or at least several tournaments). For instance, if his expected strokes after his  tee shot over the course of a year's play averages -0.4 strokes relative to the Tour table then he is driving the ball really well since he is saving almost half a stroke relative to the field (that is probably more than anyone would ever average over a season, in the Tiger Woods 2000 range). Taking that same example a step farther, a player might notice that he averaged -0.4 strokes/hole with his tee shots when in tournaments where he finished in the Top 10 and +0.2 strokes/hole with his tee shots when he missed the cut. That would be evidence that his driving was a make/break factor in his peformance that year.

Anyway, you get the point. If we could get raw ShotLink data and construct such a table, both individual performance and relative values of distance vs. accuracy and other big-picture questions would be available without needing any regression models or high-power inferential statisics. The originator of this idea used various sources of data interprolated with his own guesstimates to come up with a table for a hypothetical scratch golfer's ability. That way a hacker can track his own rounds and figure out whether he's closer to being a good player in some parts of the game than others. For instance, by his methodology I'm within a couple strokes a round of putting at a scratch level but not even in the ballpark off the tee (due distance and penalty strokes) and from the fairway (too many shots that don't even advance the ball 1/2-shot closer to the hole). It's a fun tool if you have the data to create the table.

[BCrosby]

Good stuff Brent.

As for A.G.'s question, why stats?

The payoff for stats is better managment. They give you a more specific picture of his stengths and weaknesses. (E.g. Joe Smith can't hit a curveball but against fireball relievers he is a .350 hitter. Or Ed Brown has a high strike out ratio but allows a lot of home runs. Ozzie Smith may be a Punch and Judy hitter but he gives you extra outs a ss every game. And so forth.)

All of that would be purely academic except that there is a market for players. They are bought, sold and traded. If you are going to participate in that market, stats give you better information about what a player is worth. That's where the Bill James rubber meets the road. That's how he has been able to make teams better.

Ditto for golf. Stats are a managment tool. My guess is that few playerss really understand the weaknesses in their games. Putting? Driving? Chipping? They are almost always guessing because they have no standard of comparison. And that means most golfers waste a lot of time practicing the wrong stuff. A shot tracking system like the one outlined by Brent would be an invaluable tool along those lines.

The other obvious payoff for stats in golf is strategic decisions. When to go or layup, when to cut corners or go wide, when to play safe to the fairway or hit driver and risk long grass.

For those reasons I'm still scratching my head over why professional players - for whom missed shots have large monetary consequences - haven't explored all of this. I sure would.

Bob

 

 

[John_Conley]

Consider this from the latest issue of Golf World:
     The Tour leader in all-around stats for 2004 was Geoff Ogilvy!  Ta-da...

Ogilvy topped Singh 268-282 by adding rankings in nine statistical categories (like the game itself, low score wins!).  He was 2nd in eagles per hole, fourth in sand saves, and 7th in driving distance.  However, Ogilvy was 49th in money in 26 events.

Singh, on the other hand, won the Vardon Trophy at 68.84, despite finishing second overall in the stats.

Tallying ordinals isn't a great measure of anything if the individual criteria are not equal.  (Ordinal score is okay at best for figure skating.)

If I were the best ball striker (length, fairways, and greens), I could overcome being an average bunker player (because I'd find myself in fewer bunkers).  Also, the difference between #100 and #75 is not the same - even though summing ordinals would indicate that it is - as the difference between #26 and #1.

Now for corking bats...

There is no measurable benefit to corking a bat.  It could just as easily be left hollow once the hole is cored out.  The cork is a lighter material; the benefit to lightening a bat is in the ligthening, and not the introduction of cork.  (Others have tried a few bouncy rubber balls, hoping to somehow transfer the spring.  Also no benefit.)

There have been papers written on this.  I found them easily by Googling when Sammy's bat popped.  A longtime baseball guy kept saying the bat had more spring.  I knew that couldn't be right.  If a batter thinks it helps, there may be a placebo effect.  What the batter does benefit from is any reduction in weight that doesn't compromise the strength of the wood.  (Leaving it hollow is no different than corking it.)

You should not have any trouble finding someone's scientific explanation.

(Golf analogy... the foam in an old TaylorMade Original didn't make the ball go.  It did help to reduce the weight.  Foam was used to stabilize the sound as well.)

[BCrosby]

John Conley says:

"If I were the best ball striker (length, fairways, and greens), I could overcome being an average bunker player (because I'd find myself in fewer bunkers).  Also, the difference between #100 and #75 is not the same - even though summing ordinals would indicate that it is - as the difference between #26 and #1."

Exactly. That is why aggregating year-end Tour stats are so worthless.

The money winnings and the average score will tell you who the best players were. But nothing in the published stats tell you very much about how they got there.

In other words, any slobber-knocking idiot knows who the best player on Tour was last year. The harder (and much more interesting) question is what parts of his game separated him from the other players?

Bob

[Frank_Stanger]

Brent,

If an average golfer (between a 5 and 15 handicap) wanted to collect stats during his/her rounds in order to quantify the strengths and weaknesses in his/her game and target practice and track improvement, what stats would you suggest keeping?

The object would be to gather useful information, detailed enough to provide real insight, but not so difficult (or time consuming) to gather so as to slow play...

[Doug Siebert]

Brent,

I remember Doug Massey's posting about this, and while I recall noting my issues with it then (specifically that he pulled the numbers out of his ass for expected values for scratch, etc.) I have a big problem with using it as you suggest.  I'm not sure it is reasonable to aggregate all the different courses the pros play in this way.  A greenside bunker at Generic TPC Stadium Course #43 is quite a bit different from a greenside bunker at PV or TOC.  The rough at Augusta isn't the same as the rough at Medinah.  Maybe it'll all average out over a season, but different pros play a different schedule -- and the same guy may play quite a different schedule in consecutive years, especially if he wins a major and gets invites he wasn't getting before.

However, for someone who plays a lot of rounds on a home course, it might be useful.  If I kept those stats over the course of a season at one course, the meaning of "greenside bunker" will be pretty well defined, though it would be tilted towards the bunkers I am more likely to get into, which may not be the same bunkers you are likely to get into.  The meaning of rough is pretty similar, modulo the often large difference between late May rough and late August rough.

For putting, there is already a way to gather these stats, and in fact I've been doing it for nearly 20 years.  Well, at least writing down the length of my first putt -- I only rarely calculate the actual putting score.  Got it from a Golf magazine article years ago, and apparently it was something Sam Snead either originated, or borrowed from someone else.

You take the distance of your first putt, and assign it a value as follows:

<2 feet = 1.0
2-3 feet = 1.1
3-4 feet = 1.2
4-5 feet = 1.3
5-6 feet = 1.4
6-8 feet = 1.5
8-11 feet = 1.6
11-15 feet = 1.7
15-20 feet = 1.8
20-30 feet = 1.9
>30 feet = 2.0

At the end of the round, you add up the values for all your first putts, divide by the total number of putts you took, and multiply by 70 for your "putting score".  If you beat 70, you are putting pretty well, if you break 60 it is lights out time.

There's a few gray areas with it, such as how to handle putts from just off the green (I don't count them)  It also doesn't directly address how close you get your first putt.  Even if you have a great day and make all the 5 foot second putts you leave, you are still stressing yourself out on the greens and it clearly isn't as good of a day as one where every second putt is a tap in, even if its the same total number of putts.  Not saying it is perfect, but it is a lot more useful than just tracking your total number of putts.

I'm not really big on keeping stats on my rounds, but I do write down the length of my first putt for this (even if I only figure my putting score once or twice every other year) as well as the total putts per hole.  I also keep track of penalty strokes (writing 'L', 'B', 'W', 'H', or 'U' for each type) and write down what shot it was anytime I hole out from off the green.  But I don't track stuff like fairways (too depressing) or greens (though I suppose it would be easy to go back and figure since I have my score and the number of putts recorded)

I still find the best way to review how I played is to replay the round in my head and try to figure out how many shots I threw away.  Looking at the round I played last week, I shot 75, but threw away the following shots:

2 lost balls (4 strokes)
3 missed putts of 5 feet of less (2 shots -- can't make 'em all)
4 putts from 15-30 feet hit dead on line but less than 6" short (1 shot -- shoulda made at least one)

That's 7 shots thrown away, which is pretty good for me, I'm happy anytime I throw away less than 10.  Mainly because I had 14 GIR, plus two "GIR after reloading and hitting 3 off the tee." (and 2/12 FIRs, shows how important those are!)  This year I've been throwing away shots right and left (literally) with my irons, but I had my best iron play of the whole year.  I hit some bad shots, but nothing bad enough to really count it as throwing shots away -- if I took it to an extreme I could have myself shooting in the 50s every round with "if onlys", but that's clearly not too useful unless you are Tiger

So if I'd had any total chunked irons or chili dips or what have you that are bad enough to throw away an entire stroke (or more, depending on where) I'd count those.  Something that's an egregious shot, like pulling it left into a bunker from 75 yards or something I'd count as a half shot, since I still had an opportunity to recover but made it hard on myself.

[Jason McNamara]

If I were the best ball striker (length, fairways, and greens), I could overcome being an average bunker player (because I'd find myself in fewer bunkers).  

You'd be Jack Nicklaus.  

Jason

[Brent Hutto]

Frank and Doug,

I have some ideas in response to both of your posts but may not get a chance to write anything much today. It's quite interesting stuff, though. Maybe this evening...

[JohnV]

If I were the best ball striker (length, fairways, and greens), I could overcome being an average bunker player (because I'd find myself in fewer bunkers).

The top 5 in GIR were:

Joe Durant, Vijay Singh, Tom Lehman, Sergio Garcia and Briny Baird.

If you look at their ranking for number of bunkers hit per round they came in: 2, 71, 4, 115, 56 respectively out of 196 players.

Their save % ranked: 182, 71, 157, 111, 178 respectively.

So, it appears that Durant and Lehman are certainly players who hit a lot of greens and miss bunkers.  The others are not quite so good at missing bunkers.  It could be argued that some players  (ie Durant and Lehman) are good at hitting greens because they play away from the flag and to the center of the greens while others go at the flag and hit their target a lot, but when they miss the frequently hit the bunker guarding the hole (ie Sergio).   Given Durant and Lehman's save %, they probably should try to avoid bunkers.  What is surprising is that Sergio isn't a better bunker player, or perhaps it is his putting.

[A_Clay_Man]

Exactly. That is why aggregating year-end Tour stats are so worthless.

Worthless only in the context of past performance. BUT, I find them interesting in predicting future results.

What Geofff Ogilvy's stats tell me, is that he has a great chance to move up the money list next year.

[BCrosby]

Adam - Agreed, sort of. It tells us that Ogivie is a good player. But not much more than that. For example, what are the strengths of his game?
_________________________________________

In terms of hierarchies of the stats now available, would people here agree generally that the strongest predictor of the quality of play would be someone who finished high in GIR AND in putts per GIR?

(That means you are hitting a lot of greens AND leaving it close to the pin. The latter conclusion is justified because no one sinks putts longer than 10 feet on any regular basis.)

Was that borne out by VJ's rankings last year in those two categories?

Bob

[John_Conley]

Brent,

If an average golfer (between a 5 and 15 handicap) wanted to collect stats during his/her rounds in order to quantify the strengths and weaknesses in his/her game and target practice and track improvement, what stats would you suggest keeping?

This is easy.  I would (and did when I used to enter amateur events) track the following...

GIR (broken out for par 3, 4, 5).  My goal was 2/4 on par 3s, 4/10 on par 4s, and 3/4 on par 5s.  More on a good day.

Fwy hit.  Anything over 50% for me is good.  Most important is where the ones not in the fairway wound up!

Sand Saves.  I should be 2/3 when I draw a good lie, so a total of 1/2 or better is acceptable.

Up and down.  Try to get up to 1/2.

Wasted shots.  Leave it in a bunker.  Trying to chip out of the trees and failing to do so.  Etc...  This should be down close to zero when you are on your game.

Birdies.  Three in a round is nice and really helps your score.  It can be an attainable goal if you just stuff one iron shot, make one putt on the greens you hit, and get around the green in two on one par 5 per round.  Playing well, I feel I should be able to average 2 per round.  

Putts per GIR.  I assume that I'll always have one 3-putt per round.  This is entirely normal, even for a good putter.  A total of 1.8 is excellent.

Penalty shots.  May be more or less a problem depending on the courses you are playing.  In Minnesota, I never wanted more than one in a round.  (Count OB as a two-stroke penalty, since it really is.)

The goal for me was to have scores of 75-77 as a "target" on a normal day.  I can get there if I hit 9 of the greens and play those holes -1.  Getting up and down on 4 of the remaining 9 holes is +5 for a total of +4.  This allows for:
* missing half the greens
* 3-putting once per round
* failing to get up and down more than half the time

You can shoot lower scores (around par to +2) when you overreach your goals.  (Hit more than half the greens, don't have that three putt, or get up and down more times.)

Keep these statistics for yourself for 10 rounds and look for a pattern.  You'll see WHERE you lose shots.  If you cannot hit the greens often on par 3s you will know you can work on the tee shots on the driving range.  If you only hit 40% of the greens on par 5s you are somehow mismanaging by not playing to your strengths.  Once you see the data you will be able to set YOUR goals.  As always, much benefit can be realized by working on your chipping and sand play.  (I've always felt like those are the easiest places to save shots.)

You will be able to introduce your own things to track in time.  Some examples are successful approaches from 100-150 (believe it or not, you can reach the above goals with a number as low as 60%) or times lagged to within 3' from outside of 20'.  It really depends on what patterns you see in your own game.

[A.G._Crockett]

John Conley,
That's a pretty good statistical breakdown of a round, especially the breakout of GIR.  I'll use that myself, and pass that on to my HS players; it is a little more sophisticated than what I had been using.

As to the bat corking, I know the corking itself doesn't add anything.  I think that is to simply keep the sound similar to the regular bat; it's the weight change, of course, that accounts for the distance gain.  But, since "corking" is the terminology used, and my son wanted to do a science project on corking, then corking it was to be!  (If it would get him more interested in school, I'd pee in the bat!)

Actually, our stats showed about a 4% gain due to the weight reduction after drilling out the bat, which is why HS and college players play with a 3 oz. drop (length to weight) as opposed to the 8 oz. drop that younger players use, and professional players use wood bats which generally have no more than a 3 oz. drop, and often less.  

[John_Conley]

Correct.  The cork is desirable is due to the sound muffling.  But cork (or bouncy rubber balls) do not add a spring to the bat, no matter what old lore says.

If I were talking to a HS team, I'd keep standardized statistics and tailor the goals.  (#1 player may be able to average 60% of GIR, #5 may not ever be able to reach a par 5 in two.)  At a minimum, they should be able to get up and down 40% of the time when faced with a realistic chance (inside 30 yards with no trees or other troubling circumstances) and should work to do the same out of greenside bunkers.  Incent the activity and it will lead to better scoring.  For example, give golf balls to the kid who gets on the green for the most par 5s.  This will cause them to focus on management over miraculous shots.  Of course, anyone who wants to play professionally has to get their stroke average on par 5s below 4.6, so they'll have to be more aggressive when they get older!

I think the one thing most people are surprised about when they see their statistics is how seldom they hit the GIR on a par 4.  Anything over 40% and you should have no trouble maintaining a 5 handicap.  Get it up to 60% and you are probably dealing with a scratch golfer.

My figures assume appropriate tees as defined by the ones that leave you with (almost) no woods into a green on par 4s after well struck drives and only a few wedges (or shots under 125) on the shorter 4s.  A strong player in HS today will score very well on the short tees they use, so adjust the GIR data accordingly once a pattern has emerged.