In addition to platonic stirrings for "self-determination" and to narrow group interest, there was a motive for craft autonomy which could pass muster both as strictly social and realistic. The fact was that the autonomous craft union could win strikes where the centralized promiscuous Order merely floundered and suffered defeat after defeat. The craft union had the advantage, on the one hand, of a leadership which was thoroughly familiar with the bit of ground upon which it operated, and, on the other hand, of handling a group of people of equal financial endurance and of identical interest. It has already been seen how dreadfully mismanaged were the great Knights of Labor strikes of 1886 and 1887. The ease with which the leaders were able to call out trade after trade on a strike of sympathy proved more a liability than an asset. Often the choice of trades to strike bore no particular relation to their strategic value in the given situation; altogether one gathers the impression that these great strikes were conducted by blundering amateurs who possessed more authority than was good for them or for the cause. It is therefore not to be wondered at if the compact craft unions led by specialists scored successes where the heterogeneous mobs of the Knights of Labor had been doomed from the first. Clearly then the survival of the craft union was a survival of the fittest; and the Federation's attachment to the principle of craft autonomy was, to say the least, a product of an evolutionary past, whatever one may hold with reference to its fitness in our own time. Whatever reasons moved the trade unions of the skilled to battle with the Order for their separate and autonomous existence were bound sooner or later to induce those craftsmen who were in the Order to seek a similar autonomy. From the very beginning the more skilled and better organized trades in the Knights sought to separate from the mixed "district assemblies" and to create within the framework of the Order "national trade assemblies."[26] However, the national officers, who looked upon such a move as a betrayal of the great principle of the solidarity of all labor, were able to stem the tide excepting in the case of the window glass blowers, who were granted their autonomy in 1880.