Solheim's Anser putter a revision of the original PING was used by Julius Boros to win the Phoenix Open in 1967, and sparked a trend that's continued to this day: heel-toe weighting in putters (and perimeter weighting in all other clubs). Solheim's PING putters spread the weight towards the heel and toe to minimize distance loss on off-center hits, effectively enlarging the sweet spot. Almost every putter today uses heel-toe weighting.