Lots of greens slope from back to front, so if you have a front pin it is often better to be a couple of yards short of the green and below the hole, rather than putting downhill from the middle of the green.
A couple of things here that add to my previous remark :
1. The pod went on to say that an analysis of pga pros revealed that the ones that were misclubbing the front pins scored worse, and were more likely to lose their cards, than those that did not.
2. Again, for analysis of good players, downhill/uphill is a much smaller factor in making a putt that the absolute distance. Additionally, making from off the green is much less likely than making from on the green.
Now, all of these are for pros/elite ams, so I realise that there are limits for useful comparison to 'normal' people like us.
It might not seem this way, but I don't have a particular axe to grind on this, I'm just relaying information gleaned from research by people that actually have the time to do it. IIRC it is based on work by Scott Fawcett who is referenced on this thread somewhere by someone else. He is very hot on stats and game management.
I'm currently experimenting with the overclubbing myself, early days etc, but it seems to be a good thing.