Digging into the belly putters numbers
Putting technique controversy is nothing new.
In 1967, the USGA and R&A agreed to prohibit players from straddling the line of their putt. The great Sam Snead had developed a "croquet style" of putting that grew in popularity with players struggling on the green.
Trivia questionWho is the only player to rank inside the top five in strokes gained putting each of the last three seasons? (Answer below)
Fast-forward 45 years, and the belly putter is now in the proverbial cross hairs. Wins in three of the last five majors (Keegan Bradley at 2011 PGA, Webb Simpson at 2012 U.S. Open and Ernie Els at 2012 Open Championship) will do that.
Els' rediscovered recent success says the switch worked, but what do the specifics tell us? Whether or not the switch has been effective for a few players isn't at the core of the debate, but the statistics can lend some clarity as to the impact the belly putter has had.
For starters, not many elite putters are using the anchoring method. Look at the PGA Tour's leaders in putting's definitive metric, strokes gained putting. Not a single player ranked in the top 20 in SGP this year primarily used a long putter. The highest-ranked player using one? Carl Pettersson, who is 21st.
When the Big Easy made the switch, he didn't turn into Ben Crenshaw. Instead, the numbers say it made an atrocious putter simply below average.
In 2011, Els was 178th to 183rd on the PGA Tour in several categories, including strokes gained putting, make percentage inside 10 feet, putts between 4 and 8 feet and putts between 10 and 15 feet.
Els skyrocketed into mediocrity in each of those categories in 2012. He moved to 112th in strokes gained putting, 85th inside 10 feet, and 91st between 4 and 8 feet.
Adam Scott rode a similar escalator to below-average putting when he switched.
In 2010, Scott's last full season with the regular-length flatstick, he was 186th on the PGA Tour in strokes gained putting and 192nd on make percentage inside 10 feet. In 2012, Scott was up to 148th and 111th in those statistics. That's a definite improvement, but not exactly Brandt Snedeker territory.
A common thread between the switches made by Els and Scott was their huge jump in make percentage on putts between 10 and 15 feet.
Els' ranking in that statistic jumped 55 spots from 2011 to 2012. Scott ascended 74 places -- from 157th to 83rd -- from 2010 to this season. Bradley and Pettersson also rank inside the top 40 on tour in the category.
But not all of the numbers reflected glowing improvement for Els and Scott.
In 2011, Els had 41 three-putts in official PGA Tour events. Want to venture a guess on how many he had in 2012?
That's right: 41.
In 2010, using a conventional putter, Scott ranked 189th on putts between 4 and 8 feet. In 2012, he was just 166th.
The switch doesn't work for everybody. For one week in 2011, Phil Mickelson gave us one of golf's most bizarre sights in recent years when he tried using a long putter.
Lefty finished the 2011 Deutsche Bank Championship tied for 10th, but it wasn't on the strength of his putting. Mickelson made just one putt longer than 15 feet all week; he was 61st in the field in strokes gained putting. He also missed seven putts inside 10 feet.
Question: Who is the only player to rank inside the top five in strokes gained putting each of the last three seasons?
Answer: Luke Donald
Switching back was the right call for Lefty. With a conventional putter in 2012, he finished 10th on tour in strokes gained putting and made 55 putts of 15 feet or longer.
Because players who have dabbled in long-putter experimentation tend to go back and forth with using the club, it can be difficult to get a firm grasp on what a switch means statistically.
One thing is certain: As long as the anchoring of belly or long putters is allowed by the rules and there's a chance they help a player succeed, then they'll continue to be in some players' bags.
Justin Ray is a senior researcher with ESPN Stats & Information. He has contributed to ESPN's golf coverage since joining the network out of college in 2008. He is based in Austin, Texas, with the Longhorn Network. Send comments and suggestions to Justin.Ray@espn.com.