Trying to understand "best difficulty"

What are your settings?

Your difficulty has to be higher than the network difficulty to mine a block. While it is true that the better your difficulty is the closer you came to winning a block, second place is still the first loser. If you want to improve it you can always adjust your settings to give it some more gas. 😉 

Think of it as an indicator of how close you've come to solving a block. To be successful your difficulty needs to exceed the network difficulty of the block you are mining.

It's fun to see how close you got, but it doesn't really mean anything unless you exceed the current network difficulty. Remember if you're mining BTC on a bitaxe it's the equivalent of buying a lottery ticket as far as probability goes lol.

Anything lower than network difficulty is just a lottery ticket.