For all those who have been through their coaching qualifications, you will be only to aware of the discrimination between technique and skill based drills - unopposed or opposed.
The simple rationale being we have to know what to do before we can apply it in a competitive environment. Hence the technique/unopposed emphasis should be the initial part of the coaching process i.e. explaining how to do something. However the majority of my coaching observations seem to highlight coaches repeatedly doing the same unopposed drills. From my observations repeated exposure to unopposed drills will create players who are fantastic at unopposed drills e.g. Do a lot of SAQ and you will become excellent at SAQ but weak in an opposed environment - namely a game. It is also easy, self gratifying and ensures the coach stays the fountain of knowledge rather than the enabler of mastery and of course repeated exposure to drills that have a tendency to be boring and easy will ultimately become detrimental to development, thus coaching becomes destructive rather than constructive
Football is waking up to the concept of Myelination -if you don't know what it is - here is a brief explanation of how it applies to world of Football coaching
Definition
What that means in Football
Myelin is an insulation that forms around the neural pathways - the thicker the insulation the faster and more precise the brain signals. Thus performing a delicate football skill is a consequence of continued practice - i.e. the more you practice a particular skill the thicker the myelin becomes - hence repetition is the root of mastery BUT only the right repetition fuels the act of myelination. A simple example would be the guys who are brilliant at Ball juggling - they are incredible at feats of juggling but not the driving force we would expect in a game situation because they master juggling rather than the game of football
Daniel Coyle has written a book entitled "the talent code" the book goes into great detail regarding sport, mastery and myelination. The Football perspective is however slightly different. A golfer has few variables to deal with when playing a shot i.e. lie. distance, weather and obstacles, hence golfers practices will be dominated by unopposed practice whereas football has multi-direction, moving ball, distance, opposition positions, moving team mates etc, etc
Hence we can only achieve meaningful attainment of mastery by repeated exposure to the conditioned drills that replicate the environment to which they will be applied i.e. TEACH THE GAME NOT THE DRILL
So do unopposed drills have any value - YES when introducing a concept but if you stay in this stage for too long player development will be hindered rather than enhanced. Ask yourself how many of Lance Armstrongs 7 Tour De France wins do you think he attributes to his time spent on stabilisers - thats the equivalent of unopposed drills - how often do think Lionel Messi attributes his wonderful skills to the time he spent amongst the dribbling cones on the training ground