This is a question that as a competitor you should ask all the time.
Because it is the same question your opponents are asking themselves. They are watching tape, doing Google searches on your name, and asking friends what are your strengths and weaknesses. Based on this research, they will be developing a game plan on how to defeat you.
This is way it is hard to be a champion for a long time. As a champion, you are in the spot light. Everyone knows what you do and has plenty of research material at their disposal. They can pin point chinks in the armor and exploit them if you do not keep reinventing yourself.
To stay on top of your game, you need to know where your enemy can hurt you the most. If you are totally helpless in the half guard, this is an area that you should give attention to in training. Keep in mind that you will always have a specialty – one particular area that you are great at. I wouldn’t tell you to try and become an “expert” in all areas, as this would be nearly impossible to do – not to mention a waste of time. All you need to do is be prepared enough to have 1 technique that you can use effectively.
Analyze yourself as if you were going to fight someone with your exact skill set and ask yourself:
Armed with these answers, you have a blueprint on how to defeat yourself. This gives you great info on what you need to improve on. Besides improving your strengths, bolstering your weak spots is a top priority.