As best I can, I'm going to research the numbers on current players vs. each other and Aaron and Ruth.
Ken Griffey Jr.
At the age of 36, Ken Griffey Jr. now has 537 homeruns. At the age of 36, Hank Aaron had 592 career homers, a difference of 55 homeruns. Griffey has amassed his homerun total playing in 2,127 games, while Aaron had played in 2,576 games by age 36, a difference of 449 games advantage to Aaron. Junior has hit his 537 career homeruns in 7,878 at bats, while Aaron hit his 592 homeruns by age 36 in 9,952 at bats, a difference of 2,074 at bats advantage to Aaron.
Analysis: By age 36, Hank Aaron had hit 55 more homeruns than Ken Griffey Jr. while playing in 449 more games and amassing 2,074 more at bats. In essence, playing 2.7 more seasons than Junior.
At age 36, Babe Ruth had 611 homeruns, 74 more than Griffey and 19 more than Aaron. He accomplished this while playing in 2,080 games, 47 less than Griffey and 496 less games than Aaron. It took Ruth 7,045 at bats to hit his 611 homeruns, 833 less at bats than Junior, and 2,907 less than Aaron, a staggering number.
Analysis: Aaron had 19 less homeruns than Ruth at age 36, while playing the equivalent of 3.06 more modern seasons than the Babe. A more prolific homerun hitter than either Griffey or Aaron, while Griffey is more prolific than Hammerin' Hank.
At age 36, Barry Bonds had 567 homeruns. This is 30 more than Griffey, 25 less than Aaron and 44 less than Ruth. Bonds accomplished his age 36 numbers by playing in 2,296 games, 169 more games than Griffey (roughly one season), 280 less games than Aaron and 216 more than Ruth. Bonds numbers came in 7,932 at bats, just 54 more at bats than Junior, 2,020 less at bats than Aaron and 887 more at bats than Ruth.
Analysis: At the age of 36, Griffey and Bonds are almost equal on the homerun pace. Ruth is by far the more prolific homerun hitter of the four, and Aaron had a huge advantage over everyone by playing in many more games and gaining a large advantage of at bats.
Age 36 one homerun per # of at bats:
At the age of 41 now, Barry Bonds has 708 career homeruns. At the same age, Hank Aaron had 745 homeruns, while Babe Ruth retired at the age of 40 with 714 homeruns.
Barry Bonds has played in 2,732 career games. At the age of 41, Hank Aaron had 3,213 games played, an advantage of 481 games (2.96 modern seasons more than Bonds). Barry has 9,145 career at bats, while Aaron had 12,093 at bats at the age of 41, an advantage of 2,948 at bats.
Analysis: At age 41, Hank Aaron had 37 more career homeruns than Barry Bonds has while playing the equivalency of almost 3 more modern seasons. This makes Bonds a more prolific homerun hitter than Aaron.
Now, let's compare Bonds and Ruth's career numbers. 708 career homeruns for Barry, 714 for Ruth. Ruth played in 2,503 games, 229 less than Barry Bonds. The Babe had 8,398 at bats, 747 less than Bonds.
Analysis: No matter what happens going forward, the numbers show that Babe Ruth was a better homerun hitter than both Bonds and Aaron.
Age 40/41 one homerun per # of at bats:
Alex Rodriguez has hit 430 homeruns now by the age of 30. By the age of 30, Griffey had hit 438 homeruns. Rodriguez has played in 1,595 career games. Griffey had 1,680 games at age 30, an advantage of 85 games. ARod has 6,208 career at bats. Griffey had 6,352 at bats, an advantage of 144 at bats. The two are so close at age 30, it's eery, however, ARod is ever so slightly the more prolific homerun hitter with one homerun every 14.4 at bats to Griffey's one homerun every 14.5 at bats.
At age 30, Hank Aaron had hit 366 homeruns. He did this in 1,656 games, 61 more games than ARod. Aaron had 6,510 at bats, 302 more than ARod. Rodriguez has 64 more homeruns, playing in less games and with less at bats.
Ruth at age 30 had 309 homeruns (he was primarily a pitcher until age 24). Ruth played in 1,198 games and had 3,923 at bats. 121 less homers than ARod while playing in 397 less games (2.45 modern seasons) and having 2,285 less at bats.
Bonds at age 30 had 292 career homeruns, 138 less homers than ARod. Bonds had played in 1,425 games, 170 less career games than ARod (roughly one modern season). Bonds had 5,020 career at bats, 1,188 less at bats than ARod.
Age 30 one homerun per # of at bats:
Analysis: Bonds was the better homerun hitter than Aaron by age 30, but only slightly. Griffey and Rodriguez were virtually equals, while Ruth was once again more prolific.
Albert Pujols has 204 homeruns at the age of 26. He has put up this amount of homers while playing in 792 games and accumulating 2,960 at bats.
At age 26, Ken Griffey Jr. had hit 235 homeruns, 31 more than Albert, while playing in 1,057 games, 265 more games than Pujols. Junior had 3,985 at bats, 1,025 more than Pujols.
Aaron at age 26 had hit 219 homeruns, 15 more than Pujols. Aaron had played in 1,039 games, 247 more than Pujols. Aaron had 4,114 at bats, 1,154 more at bats than Pujols.
Ruth at age 26 had hit 162 homeruns, 42 less than Albert, while playing in 685 games, just 107 less than Pujols. Ruth had 2,107 at bats, 853 less than Pujols.
Bonds at age 26 had hit 142 homeruns, 62 less than Albert, while playing in 870 games, 78 more than Pujols. Bonds had 3,111 at bats, 151 more at bats than Pujols.
ARod at age 26 had hit 298 homeruns, 94 more than Pujols, while playing in 1,114 games, 322 more than Pujols (roughly 2 modern seasons) and accumulating 4,382 at bats, 1,422 more than Pujols.
To compare, Adam Dunn is also 26 and has hit 159 homeruns while playing in 663 games and accumulating 2,278 at bats.
Age 26 one homerun per # of at bats:
Analysis: We may have the privilege of watching three of the most prolific homerun hitters in history playing right now. If Pujols, ARod and Dunn can all stay healthy, the sky is the limit. Take a long hard look at just how special Adam Dunn is Reds fans, don't take him for granted.