Just goes to show you even a supposedly reputable writer such as Robert Edgren cannot be taken for their word.
In some cases you can respect a writer by his word, but when dealing with a technology the writer can't measure or research its best to do your own. Bravo for accepting the truth. In the end, it doesn't matter. Dempsey and Louis clearly had fast hands.
When i was 15 years old , i scored a 632 on one of those machines. Im 26 years old now and i would love to find out how much higher my score would be today. Unfortunately, those damn machines are not very easy to find lol
Honestly, I think these things are probably a gimmick. Seems like some machines are harder to get high scores on than others. Also, the "science" behind these things are probably dubious. Are they using sensors to measure how fast the bag gets pulled back? Or do they use sensors to measure the force of the bag? Is the methodology standardized between all the machines?