Ken Dryden explained where finishing your checks came from. It was an invention by some coaches that allowed slower players to compete with faster, more skilled players. However it also brought to the game an epidemic of concussions in hockey.
Here's the problem. We weren't born yesterday. We can tell propaganda when we see it.
Think about all the implications being made by the statement above.
A. There is a known origin for the phrase "finish your checks." That is as plausible as there being a known origin for the phrase "finish your dinner." It is plausible that the phrase has no distinct origin, or has multiple origins. One person may give one account that could seem plausible, but that is at the very best an incomplete story and at worst meant to mislead.
B. Intent. How do you adjudicate the intent of someone's actions unless specifically enumerated by the people in question. It's basically impossible. Firstly, the physics of what you're saying don't really make sense because slow players who have less momentum have a much easier time redirecting than fast players. Secondly, you make a very specific causal claim about the origin of a phrase and real life events due to the malicious architecture of a few individuals dubiously attributed with this invention. This seems highly suspect for many reasons, including simply the fact that there have always been concussions in hockey.
C. There is no set definition for this phrase. Now I will grant that this parameter can be needlessly difficult to pass at times. But "finish your checks" isn't a phrase like "atomism" where we know what is meant when the phrase is being used. Different individuals use the phrase different ways and in different contexts.
So, please, try to think of what you're trying to convince us of. Yes, I know you read a book and you thought his line of thought was convincing. But you're trying to convince us that a nebulous phrase originated from a definite location perpetrated by individuals with expressed intents and directly led to the phenomena being described. The likelihood that this picture captures any significant amount of truth is ridiculously low, and it appears to me that you're offering a significant credibility excess (an epistemic injustice) to this author whose name you keep invoking.