By Tony Jimenez WOBURN, England, (Reuters) - U.S. Masters and U.S. Open champion Jordan Spieth could go down as the greatest putter golf has ever seen, Europe's Ryder Cup talisman Ian Poulter told Reuters on Monday. World number two Spieth has won four times this season and is breathing down Northern Irishman Rory McIlroy's neck at the top of the rankings. "The putts Jordan is holing is the reason why he's putting himself in position week in week out," Poulter said. More...