Here are some of my observations.
1. Both had their highest single season HR total at age 37.
2. Aaron had his highest 5 year HR total between ages 35-39, Bonds
between 36-40.
3. Both seemed to reinvent themselves as pure sluggers at age 35 when
things like base stealing ability declined
4. Both had their highest OPS at age 37, Bonds 1.378, Aaron 1.079
(Aaron had far fewer walks which was the nature of the game at that
time)
What it comes down to is if Aaron could put up those numbers without
cheating then why couldn't Bonds?
I've read Game of Shadows and you would think it was the alleged
steroid abuse which led to him hitting 73 HR's in 2001, but the book
indicates he was taking steroids much longer than just that one
season, yet his next best HR total is 49. If he was rampantly using
steroids during those years why didn't he go on a McGwire and Sosa
like tear of hitting 60+ each year. The 73 home run season looks like
an aberation compared to the rest of his career. Placed in the context
of his entire career could the 73 HR season just be an anomaly like
Seattle winning 116 games, or Atlanta winning 14 straight division
titles?
I'm not implying that he didn't take steroids as I believe he probably
did, but I also believe that a large number of players including the
pitchers he faced were using steroids, which in effect leveled the
playing field giving him no great advantage over everybody else. The
numbers to this point in his career look to me to be a tribute to his
talent and longevity much like that of Hank Aaron.
Quite interesting...
There's no doubt in my mind that Bonds was a first-ballot HOF even had
he not used steroids. However, you're focusing on the wrong things.
You've stated that since Aaron had his highest unadjusted OPS at age
37 just as Bonds had. However, look at OPS+. Aaron's 194 in 1971
(age 37) and 177 in 1973 (age 39) are not out of scale with his
previous top 5 seasons (181, 179, 178, 170, 168).
What Bonds did was to go from a Mickey Mantle-like career to a Ruthian
one starting with age 35. His best OPS+ were at ages 27-28 (205,
206). Starting at ages 36 on he put up 262, 275, 231, and 260. The
reason why Bonds never approached 73 has something to do with the fact
that he had 68, 61 and 120 *IBB* after that season (compared to mere
35 in 2001). Whether Aaron just had good genes or was aided by PEDs,
his spike never approached Bonds' longer spike.
You mention how Bonds OPS+ increased so dramatically in later years,
but that would been as much down to the increased number of walks he
was getting than the increase in power, and Aaron's walk total didn't
increase anywhere near as dramatically as Bonds. You can't punish him
for developing better patiance at the plate and for the fact that
managers were too scared to face him.
During those 4 years you mention where his OPS+ was 262, 275, 231 and
260 he was averaging at least 50 more walks than in the two years
where his OPS+ was 205 and 206. I'm not sure how much that would
account for the increase in OPS+, but I suspect it would be quite a
lot.
Also you imply he would have hit over 60 home runs regularly if he
wasn't getting so many IBB's in those seasons, but if he was getting
50+ at bats rather than walks in those later years, at his rate of
about 1 home run every 8 at bats he still would have been in the low
50's for home runs.