Clean game argument and Allison's 900 are totally different issues. There is no need to defineva clean game except in the individual event situation where there is some special award. In that situation a clean game is whatever the individual definition defines it.
In Allison's case his 900 was thrown out under an ABC lane conditioning rule. The fact that the rule was applied in an arbitrary and capricious manner, and without adequate technical measurement methodology is what makes so many if us disappointed
Here is my point about why I brought up the 900.
First off, it's about agreeing to the rules as written, and just accepting them, as stated. I think rules need to change as the environment changes. Example, 35 years ago, there really wasn't a need to have a rule in place to limit a handicapped game to only 300, however, in today's environment, we needed to change that rule.
Second, both are "achievements" of the individual nature, so it's not that far off from each other.
It's about comparing an "accomplishment" that was much harder to achieve 35 years ago then it is today, based on the bowling environment. As stated above, rules need to be current and with the times. If using the same ball and bowled today, Glenn's 900 would be accepted because they don't check the lanes after every single award score shot.
40 years ago, I can understand saying a "clean game" consists of one mark in every frame. But not in today's environment that is so much easier to strike and use balls that go so much straighter for spares.
Probably why there is only an all spare award from usbc, and not a clean game award. There is a glaring flaw in the logic.