Nothing gives you more confidence standing over a pressure-packed 5-footer like a putter you've won many wars with, or have had great success with in the past. The positive experiences Goosen had with that putter had more to do with that ball going in the hole on Sunday than any stroke he put on it.
Goosen flirted with a belly putter for several weeks and even played three events with it, but went back to the shorter putter the week prior to the WGC-CA Championship. I'm not a big fan of the belly putter because it forces you to hinge your wrists, but sometimes it does your game – or, in this case, putting stroke – some good when you make a club switch because it forces you to look at what you're doing differently. You go back to being more reactionary than analytical, which is a good thing. Even Goosen suggested that the belly putter was a 'good training aid' in his post-round press conference on Sunday.
But I go back to something he also said in his remarks. Goosen said of the old C-Groove putter: 'Pretty much all of the tournaments I won, I won with that putter. So it seems to be behaving again.' Notice he didn't talk about the events he lost with that putter. It doesn't hurt to experiment every now and then, but if you have a club that has performed outstandingly for you in the past, keep it in your bag. More often than not your struggles have nothing to do with the club. It's more in your head.