The non-fine-tuning hypothesis, non-design, or even, dare I say, Darwinism have several different forms but, broadly speaking, is anything other than fine-tuning (or the design hypothesis). There are three primary non-fine-tuning (non-design) versions: chance, necessity, and chance and necessity. Each one has different explanatory strengths and weaknesses.
It is important to qualify this explanatory hypothesis of chance, which is the present task in this post. Chance can appear as mindless chance or as a finely-tuned chance. Suppose that I have a pair of dice of which I have the ability to control what the values will be when rolled. There are two different ways I could do this. The first is to choose which value will appear for each die when thrown. If I choose two sixes then, when thrown, the dice land on two sixes. Perhaps I achieve this by placing small magnets in the dice and throw them on a magnetic table with an opposite pole so when the magnets attract the two sixes are on top. The second way I could control the values is by setting specified parameters. I could accomplish this by having the same magnets in the dice but have the table magnet with the same pole so the magnets repel forcing the dice to not land on a certain value. To give another illustration, suppose I cover the black 26 and the red 32 on a roulette wheel so the ball cannot land in those spots.
By setting these parameters there is a purposive elimination of possible outcomes but the remaining outcomes would still be a product of chance. Thus, if an argument in favor of chance, contra fine-tuning/design, it must refer to a mindless chance since the mere chance hypothesis shares categories with fine-tuning and design.