Over at Scoresheet-Talk the interesting question was raised of what makes anyone think Sean Burroughs is going to hit home runs in the big leagues when he has displayed relatively little power in the minors. Which inevitably led me to do some research. I’m not finished yet but here is a little of what I’ve found so far:

                   Age 20           MLB peak
               -------------       ---------
Player          AB  HR   Lvl        AB    HR
-------------------------------   ----------
Anderson, Ga   438   3   A, AA     647    35
Aurilia, Ri    202   3   R         636    37
Bell, Ja       494   7   AA        589    38
Bonds, Ba      254  13   A         476    73
Cameron, Mi    411   0   A         540    25
Gonzalez, Lu   272   7   A         609    57
Green, Sh      366   4   AA, A     619    49
Klesko, Ry     419  14   AA        528    34
Lankford, Ra   253   3   R         465    31

In 3109 at-bats, these guys combined to hit 54 homers at age 20. That’s just under 9 per 500 at-bats. In 5109 at-bats, they hit 379, or about 37 per 500 at-bats. Yes, this is only 9 hitters, but I’ve only looked at 45 so far. A full 20% of the players I’ve looked at have hit a lot more homers than could have been expected given only their age 20 performance.

Some of the hitters I’ve looked at, including Jason Giambi, Troy Glaus, and Todd Helton, were still in college at age 20. In 366 career at-bats in Triple-A, Giambi hit a total of 7 homers. In the PCL, a hitters’ league.

There are some guys who absolutely mashed at age 20 (Eric Chavez, Gape Kapler, Rickey Ledee, to name a few) but so far, they are the exception rather than the norm.

I’m also noticing another interesting pattern. Among the group I’ve looked at so far, of the guys who exhibited better power in the minors than in the majors, the vast majority are players who have not yet reached age 27. In other words, they may not have peaked.

I’ve got a bit more work to do with this, but I will say that as someone who believed it was possible for guys to hit for more power in the bigs than in the minors, I didn’t expect it to occur as often as I’m finding. Of course, we’ll eventually want to look for patterns to see if there are other characteristics that hitters who develop their power at the big-league level share. But that’s another story…