Short term results in a nutshell won't tell you much.  Consistently proven long term winners of the highest stakes will lose 8 out of 10 sometimes.  Marginal players at low stakes will win 9 out of 10 sometimes.Now, 13 out of 15 wins is a great sign.  If you've had consistent winning results that's another great sign.  If you haven't... well you're learning and improving so it's even tougher to measure how good you are!You have to make some assumptions in this game.  Just like an AA vs KK being 81% or whatever it is to win, nothing is certain.  If you see two large aggressive flop check raises from your opponent in the first 5 hands, flop a decent top pair 50bb deep and get it in vs his check raise, you have to assume that's a good play to make because he looks like he's check raising large often.  It's all prone to error in specific instances, but if you add up situations where you're 70-80% likely to be correct, over time, it's virtually impossible that you'll be very often incorrect.  That's one way of looking at it.As for really KNOWING that you're adjusting properly based on the assumptions you make with the information you have, practice and experience will tell you that.But definitel work on the confidence, use any insecurities to make you play more focused poker, watch more videos, post more hands and review more games.  Not every pro at the $230-5k games is just some confidence, competitive, ready to play anybody kind of guy.  There are plenty of very insecure people, they just do enough important things correctly to have more success than almost anybody else in this game.