The USGA and R&A did an excellent job presenting their case both verbally and visually for the anchoring band. But I think many of us were anticipating some meaty empirical data to back up the USGA's case that players switching to this method have benefitted.
Graeme McDowell had suggested from his conversation with the USGA's Mike Davis that there would be data to back up the argument for this ban. (Brandel Chamblee had more empirical data on Golf Channel than the governing bodies presented and I hope to get that video up later.)
Randall Mell touched on this topic:
The USGA cites no controlled studies or experiments or research to support its argument that a new definition of a stroke is needed, and that will make the decision feel arbitrary to critics. It’s the Justice Potter Stewart deal. The USGA and R&A know wrong when they see it, and they saw the game changing quickly in ways they don’t like.
The lone data seems to be this, noted by Mike Stachura.
He also pointed to usage data that suggested belly and long putters were used by three to four percent of tour players from the 1980s through the mid-2000s before a sudden upsurge.
Davis said that in 2011 the number was 11 percent, and in 2012 it was 15 percent, and as high as 20 or 25 percent in some events. More importantly, Davis said, "in the junior game, where we've seen virtually no anchoring before, all of a sudden it's started to appear. And that caused us to say, 'Is this what we really want the game of golf to be in the future?' We came to the conclusion that fundamentally that's not part of golf."
Is this enough data to make the case?