First lets pay attention to the differences in teaching hand to hand combat and fighting sports. The desire for victory is there for both but the stakes are different for both!
Learning from mistakes, is essential to form a better training system or to confirm the existence of a battle proven training system. While lucrative fighting sports which sell tickets to audience, variety of athletes and varieties of victories and losses are necessary to sell what people buy, teaching hand to hand combat should not afford of a such since it is not motivated by selling tickets to fans, and should not be motivated by collecting long term membership dues.
So how do we monitor errors in the training method and improve the process or confirm the process? Aside from overall track of victory for one trainer or another, and if it is inconsistent among his students, lets concentrate on the student or athlete and the training system to be applied on him, or more specifically lets identify the elements of proper training or lack of them thereof.
Controlling an opponent through pressure points under the constraint of reaction time is the overall formula for both combat sports and hand to hand combat. While many athletes may not be familiar with this formula and many hand to hand combat students as well, both can still be judged by this formula and portray a good reasoning for their rates of success and failure!
Problems in one training area or another should be identified and rectified:
Reaction drills: Getting the student to ingest the time limits of when to act and when it is too late to act. That includes situational awareness, physics of last split second efficient reaction, and overall using only tactics and training drills that promote solution to that problem.
Mapping drills: Getting the student to map opponents pressure points, routes to get them, and obstacles on the way such as positioning, limbs, an opponent plan to be executed that has a better overall efficiency.
Impact drills: Getting the student to proficiency hitting, kicking etc to generate maximum non projected blows and kicks to opponent's pressure points. Non projected concept incorporates efficient time saving sequence that contributes to the over all process of reaching the pressure points fast with enough stopping/controlling/distracting/ and eliminating force!
Push and Pull drills: Since push and pull causes one to try and restore his balance and comfort, it is distracting from reaching pressure points mentally and physically. One needs to get used to it and overcome the obstacles.
Prioritization: It is the best advice to anyone, anywhere, and at anytime! Specifically in a hand to hand combat training system, the process of planning, forming a training system, training, testing and executing.
Instead of looking at a successful coach as the reason for victory one should dig in deeper and find the cause and effect easily and properly and take corrective or assuring actions at all times!