What??? I probably win well over 80% of my 1v1's. Most nights I'll also win at least one 1v2. Thief is currently fine in my opinion. There are a few classes out there that are definitely over-tuned and near impossible to beat, but they are the ones that need looking at, not thief. Equal skill level. Beating worse players is easy. Beating equally skilled players nearly impossible. Same as me with Core Nade Engineer, just worse. When fighting equally skilled players you should win approximately half your fights in a perfectly balanced game with perfectly balanced classes. But Guild Wars 2 is not that game. Some builds are overpowered and some builds are under-powered. As is currently is, I do pretty well on my thief against most players and classes which tells me that the class itself is not woefully under-performing. There are definitely some OP builds out there that carry the players that use them but there are also players that are just better than I am and will probably beat me regardless of what I'm playing.