Mfing Bad Lately.

[[wcip]Angel]

More MF means more unique/set/rare/magic items.  There isn't any case where less is better for that.

What he's speaking of is "diminishing returns". In a nutshell, the more MF you get, the less your chances increase. Your chance to find stuff still increases with every % of MF you get, but it increases less.

For example: You will find many more unique and set items if you have 100% instead of 0% but you will not find that many more items if you have 500 instead of just 350.

Allow me to illustrate this with a gorgeous piece of artwork:

The higher MF you get, the flatter the line will get. It will always keep going up, but it won't go up as steep as it did from 0-100. Can also be compared with racing cars. It takes them 3 seconds to get from 0-100, but it takes them 7 seconds to get from 300-400km/h.