Tommy Armour Impact No. 4 Mallet Putter

Zero-torque is the whole story. The head is built to resist twisting open and shut during the stroke, which is a different idea to face-balancing: instead of neutralising the head's urge to rotate, this design works against the rotation itself. Golfers who leak putts in both directions can find that a genuine fix.

Thirty-four and 35 inches, right handed, in the black finish the family shares. Its face is milled with nothing set into it. This is the newest putter in the Impact range and the most opinionated of them, and it's also the only one doing this particular job, so if the zero-torque idea appeals there's no second opinion available inside the line.