For starters, we can't be 100% certain anyone was completely clean. Just like with Frank Thomas though, to me, Griffey Jr is as close as they come to 100%.
Originally Posted by Joltin' Joe
He was known for not being into weight lifting. People who were in and around the Mariner locker room during those years, have all said the same thing. His body style never changed, it was part of his charm and image as "The Kid" and "The Natural".
Griffey showed as a 23 year old, what he could do, hitting 45 HR at a 12.9 AB/HR clip. Then at 24 years of old, he poked 40 HR at a 10.8 AB/HR clip.
The back to back seasons you speak of, came during normal prime seasons, in fact directly smack dab where a typical prime would come, ages 27 and 28. His AB/HR in those 56 HR years were 10.8 and 11.3 respectively. Nothing out of the ordinary from what he proved as a youngster. Furthermore, those back to back 56 HR years were not a huge spike, as they were surrounded by seasons of 49 and 48.
Add to that, there's never been an ounce of doubt or suspicion about him.
Bonds, just like with Sosa, had a natural body type that became grotesquely chemically altered, and they had proven their capabilities on the field; natural 30-40 HR guys give or take a few. From 1997 to 1998, Sosa had an 83% increase in homers and a 34.7% increase in SA.
To put that into perspective, in 1919 Ruth hit 20 of his 29 homers away from Fenway park, had to split focus between pitching and hitting. The next season he blasted 54 HR (29 at home) as a full time hitter, the ball was livelier and trick pitches were outlawed. All that change led to an 86% increase in HR and a 28.9% increase in SA.
"With Babe Ruth drawing only $3,500 last year, where does Grover Alexander get off demanding $15,000? Babe is the best pitcher in the country today." - The Sporting News, 2/8/17
"...he has made a national reputation as a slugger all right, and it is really laughable to see the backward parade of the three rival outfielders whenever the Babe steps up to bat." - Boston Post, 8/15/15