sbrylski's chart could use some adjustments but it would be difficult to do and I don't know how to do it accurately. 1) We know that Barry was intentionally walked and pitched around to an unprecedented extent. While Hank was intentionally walked and likely pitched around to some extent, nothing has ever been done before to the extent it was for Barry. Adjusting Barry's PAs from age 36 on for the reduced number of PAs where he actually had a chance to HR would raise his curve, I would guess significantly over the corresponding raise in Hank's. 2) Barry's margin over league HRs/PA came while playing half his games in a HR unfriendly park. A better way to assess pitcher's vs. hitter's parks than citing park dimensions and guessing at how the ball carried may be to use park factors. ESPN has HR park factors for ATT/Pac Bell that rank it near the bottom. 3) I haven't been able to find historical HR park factors, maybe someone else can help. At the bottom of the page here you can click on 5 year run park factors for what you think they're worth. You can read about the methodology. The 5 year park factors for Atlanta were: 1966: 101 1967: 101 1968: 101 1969: 103 1970: 103 1971: 107 1972: 107 1973: 106 1974: 106 1975: 108 1976: 107 1977: 109 1978: 110 I'm not a stat guru but as I understand it, averaging park factors over 5 years helps with the small sample of one year but also takes 5 years to get more to the true nature of the park. I'm showing past when Hank left to show the trend of the numbers. Per sybrl's chart, '71 and '73 are the real anomalies in Hank's HR/PA. Beyond the numbers, Altanta Fulton County had a reputation as a launching pad. You can google atlanta fulton county launching pad and get hits to read about it. Hank played in a hitter's park and his line would be lower if adjusted for park factor. Some anecdotal points: 1) Killebrew and McCovey were different body types than Hank, the kind that generally don't age as well and Willie had major knee problems. 2) Hank has said and observers noted that he changed from an all fields hitter to a dead pull hitter as he aged and adapted to that park. I think the drop in Hank's doubles over this period might be indicative of this. 3) As you can see from sybrl's chart, Hank didn't keep getting better at hitting homers as you said, it went up and down like all players. 4) If you look at the park factors, Robinson played in much more pitcher friendly parks at those ages. Candlestick was mostly neutral when Willie Mays was finishing up. 5) In 1973 when Hank hit 40 HR, Davey Johnson hit 43 and Darryl Evans hit 41 for Atlanta. It was quite unusual in that day and age. Perhaps you think they all juiced together but that would lessen the secrecy aspect. Perhaps you think they all juiced independently, but just for one year. Davey never came close to that number before or after. Neither did Evans until 1985 in Detroit which had a short RF overhang. Or maybe part of it was just how the park played that year. 6) Hank never was known for long, towering HRs, just a lot of them, mostly of the line drive type. It was said his power was in his wrists. He and Barry were quite similiar in build as young players, skinny. Hank developed something of a paunch in his final years and was quite heavy with the Brewers but never underwent the changes that have been quite noticeable with Barry and many other juicers.