A short first flying phase from feet to hands makes it difficult to create an effective second flying phase from hands to feet.  Short undercut first flying phases cause the hands to touch the floor with poor body angles to  make a quick arms repulsion into a powerful turn over to the feet.  Before bad technical habits get too engrained it is wise to spend time reviewing basic drills. Like this one and many others.   /  Coaches must train their eyes to catch all kinds of big or small mistakes.  In these undercut examples the gymnast shows more turn over power.  He is still missing a proper hands placement to block and repulse the floor effectively.  Even minor mistakes deserve time and effort to be corrected.  Every skill must be refined to the maximum.  /Deep squats slow down and diminish the explosive power to begin the back handsprings.  Though there are slight personal differences in general the bend in the knees must not even reach a 90 degree angle.   /Deep squats and undercuts together weaken the back handspring immensely.  Serious basic drill reviews must be a priority.  Notice that there is not a second flying phase due to the lack of blocking and arms repulsion.