There are dozens of techniques in mma fighting and few can master them all. Most guys come from one of the main disciplines; boxing, wrestling, Brazilian Jiu Jitsu etc and so they have distinct strengths and weaknesses. A wrestler will want to get in close and get to the floor at the first opportunity, a boxer will prefer to stay upright and use a combination of hands and knees to exercise control of the fight. Whoever you are and whatever your background you will need to work on your core strength to maximise this area but you will also and perhaps, more importantly, need to hone your skills in the areas where you are weak.