Trying out new champions, item combinations and tactics against various champions to find new ways to play and (hopefully) win at League of Legends is quite a time consuming practice. If you're doing it against real people online, then you need to set aside a good amount of time for it and be prepared for lots of your ideas to fail miserably.
But that's not necessarily the case any more. One enterprising fan of the game has taken time out from the their life - quite literally quitting their job - to make the Theorycraftr, which lets you simulate games of League of Legends with different opponents, item builds and masteries/runes in order to see what might work well in a real game.
It's a very nerdy way to do things and about as far removed from the fun of playing as you can get, but if you really want to break down the numbers and your chances of taking down a certain enemy champion with a certain item build, you can see all of it.
Although some may see this as a measure of cheating or moving beyond what the game is about, for those that take it seriously and want to perhaps even make a career out of it, it's a great tool to take advantage of and the community has been very appreciative of it.
What do you think of software tools like this? Do they ruin the fun somewhat?