A numbers game: Gustavus students study steroids’ impact on home run hitters

Barry Bonds: Barry Bonds and the issue of steroids in baseball are back in the news as he chases Hank Aaron's home run mark. New statistical analysis by two college students shows that steroids don't have a huge impact on hitting homers over a long period of time.
Barry Bonds, home runs and steroids. They're all in the headlines again.

We’ve debated this topic a lot since last spring – do steroids actually help a baseball player to hit a ball farther?

Now some students from Gustavus Adolphus College in St. Peter, Minn., have crunched the numbers to try to provide some statistical analysis on the matter. Their quick answer to the question is “no.”

Tyler Kramer and Dan Johnson spent their January term analyzing the home run records of all the Major League hitters who’ve had 500 or more homers in their career. They divided those players into two groups: known or suspected steroid users and non-steroid users.

According to the abstract of their research posted in a Gustavus blog: “Based on the data from players that have hit 500 or more career home runs without the assistance of steroids, it is apparent that most major league players peak in their home run production between their sixth and tenth seasons. Players who use (or are accused of using) steroids have a peak much later in their career around their 11th through 17th seasons. Even though they are able to increase the productivity later in their careers there is no statistical evidence that steroid users are able to sustain this level of productivity over an extended period of time.”

In fact, the non-steroid users had a slightly higher home run average than the suspected users. The study found that admitted and presumed steroid users averaged 41.36 homers during their best five years while non-users averaged 43.38 over their best five seasons.

But the study also shows that steroids can provide a short-term burst in home run production. The top six single season home run marks belong to the steroid suspects.

“The probability of a steroid user breaking the record for most home runs in one year is much greater than a non-user,” the students also contend.

Their findings have earned enough national attention that this month they’ll be presenting their findings at the United States Conference On Teaching Statistics at Ohio State University.

What do you think of their conclusions? Have your thoughts on steroids in baseball changed at all through all this debate? Share your thoughts here with other Science Buzz readers.

Your Comments, Thoughts, Questions, Ideas

Gene's picture
Gene says:

Two thoughts:

1) The sample size is very small -- only 20 men in history have hit 500 or more home runs. One or two unusual data points can really skew the sample. (Ted Williams -- a non-steroid user -- spent some prime years in the military. His record is probably skewing the results.)

2) It sounds to me like this is evidence for steroid use tainting the record books.

Let's take my favorite player in the top 20, Mr. Cub, Ernie Banks. He hit 512 home runs over 16 full-to-nearly-full seasons, plus parts of three others. He peaked early -- his best stretch was his 2nd through 7th seasons, when he averaged 41.3 home runs.

At the end of his career, however, his production tapered off. In his last 6 full seasons, he only averaged 24 home runs per year. Now, steroids were not available at that time, and Ernie was not the sort of player who would use them. But let's pretend that he did, and it boosted his production to the 41.38 average from the study. That would have added another 108 home runs, giving him 620 total -- and pushing him up from 17th place on the all-time list to 5th.

Oh, what the heck...

Hank Aaron averaged 33.6 homers in his 11th - 15th seasons. If he averaged 41.38 instead, he'd have finished with 794 instead of 755.

And Barry Bonds? His best five-year period prior to suspected steroid use: averaged 39.8 home runs. Five years of suspected steroid use: averaged 51.6.

Based on this, it would seem that steroids give an unfair advantage to older players, giving them a "second peak," even if it is, on average, lower than the earlier "natural peak."

posted on Tue, 05/08/2007 - 2:31pm
steroids's picture
steroids says:

The study's abstract claims that players using steroids would not significantly increase their career numbers. But that is contradicted by their own data set. A player who reaches a "natural" peak early and starts to fade could take steroids to have a second peak later in their career...

posted on Sat, 05/22/2010 - 11:30am
Anonymous's picture
Anonymous says:

While your analysis has some merit, it it not entirely accurate. Just becuase steroids may give a player a higher peak to the second half a career does not mean that the 5 best years come during that peak. To assume that those last years would be the 5 best years of a players career does not fit with most players. So, to say that steroids would, as in your example, give Aaron around 40 more homeruns is probably not true.

posted on Tue, 05/15/2007 - 9:37am
Gene's picture
Gene says:

First, my analysis was purely conjectural. Second, I have my own doubts about the validity of the study. And third, I do not claim that any player's five best years would necessarily come during the steroid-using period. I apologize if I gave that impression.

The original study postulates that players who do not take steroids average 41.38 home runs per year in their 11th through 17th seasons. All I did was take a couple of players known not to use steroids and plugged those numbers into their career statistics, just to see what would happen. It is not meant to be definitive or predictive -- there are way too many variables.

The study's abstract claims that players using steroids would not significantly increase their career numbers. But that is contradicted by their own data set. A player who reaches a "natural" peak early and starts to fade could take steroids to have a second peak later in their career. Perhaps not their five best years, but enough to add a good number of home runs to their totals.

posted on Sat, 05/19/2007 - 7:43am
Don's picture
Don says:

YOU STILL HAVE TO HIT THE BALL. Barry has one of the best swings in baseball, bar none, he has amazing eye hand coordination, a ball hit solidly will travel no matter how big you are. Bonds also strikes out quite a bit, and flys out, and gets walked more than any player in history. That also brings down the law of averages, but the steroids is all that any one talks about. look at the whole picture please

posted on Sun, 07/01/2007 - 9:00pm
Gene's picture
Gene says:

Bonds is not a particularly easy man to strike out. He's only 37th on the all-time list, due mostly to his long career. Only once was he in the league's top 10 -- unusual for a slugger.

Walks do not count as official times at bat, so they would have no impact whatsoever on his HR-per-AB stats.

posted on Mon, 07/02/2007 - 5:02pm
CK's picture
CK says:

This is a great question, but there are several things Bonds' critics have ignored:

1) Most of the great hitters have been lefthanded, and Bonds is lefthanded. A lefthander has a natural advantage in tennis, baseball, basketball, and boxing--and maybe every other sport, too!--but baseball seems to have the highest percentage of great lefthanded athletes. A lefthanded hitter gets the so-called extra step to first base, which I actually call two steps since a righthander is naturally pulled away from first base when he swings the bat, unless he's bunting, in which case the righthander might actually have an advantage. Of the great home run hitters, Babe Ruth, Reggie Jackson, Ted Williams, and Bonds are all lefthanded.

2) Bonds is a student of the game, maybe the best since Ted Williams and maybe better. I won't go into a long list of all the training Bonds has been through, but there's martial arts, weightlifting, underwater stuff, just far more than anybody's ever done plus better nutrition.

3) Access to superstars. Bonds' father Barry Bonds was a superstar, for a while. HIs godfather Willie Mays was the best all around player ever. So the scientific cliche that we stand on the shoulders of giants has special meaning here! Bonds as a kid wasn't just playing catch with his dad, he was playing catch with superstars.

Now if you look at Bonds' stats, yes, he went up in weight and statistics in his late 30s, but he always showed home run potential.

73 Home Runs

This is the one question mark in my mind, along with the BALCO investigation. Mark McGwire has admitted using steroids, and he and Bonds are the only 70 home run hitters ever. How did a man in his late 30s--who'd never hit 50 home runs before--suddenly become a 73 home run hitter??? Everything else Bonds did seems logical to me with all his other assets, advantages, and training. I can accept the .370 season, the 700+ home runs, and all the other great stats because of Bonds raw competitiveness, drive, but terrific selection of what pitches to hit and what not to, plus simply being avoided by most pitchers--but 73 home runs in one season in his late 30s stands out, to say the least.

posted on Fri, 07/06/2007 - 7:57am
Gene's picture
Gene says:

You make a lot of good points. One quibble -- being left handed, and having an extra step or two to first base, would not have any impact on home runs, which almost always go completely out of the park. OTOH, one could argue that the majority of pitchers are right-handed, and left-handed batters are supposed to have an advantage against right-handed pitchers. I don't know how true that is, nor what Bonds' record against RHP would be.

posted on Fri, 07/06/2007 - 11:36am
Anonymous's picture
Anonymous says:

hint of sarcasm

it is amazing that one can get better over 35 when one starts to slow down but hey i dont use the juice

posted on Fri, 07/06/2007 - 7:27pm
Anonymous's picture
Anonymous says:

bonds has 455 homeruns against RHP

posted on Fri, 07/06/2007 - 7:34pm
Gene's picture
Gene says:

Yes, but he has faced far more RHP than LHP. It would interesting to know if there is a significant difference in his AB/HR vs. each type of pitcher. IF, for example, he has hit 1 HR per 10 AB against righties, and only 1 HR per 20 AB vs. lefties, then we could say that yes, being a left-handed hitter has given him an advantage. But I do not know what the real figures are. Does anybody?

posted on Thu, 07/26/2007 - 4:16pm
Anonymous's picture
Anonymous says:

He was good before he did steroids but his head grew and that hardly ever happens unless you're on some type of steriods.

posted on Sat, 07/07/2007 - 1:28pm
Anonymous's picture
Anonymous says:

This whole discussion is ridiculous. If he had not taken steroids, his body would have given out long ago and he would not have had the chance to hit home runs into his 40's. THAT'S the issue.

posted on Thu, 07/26/2007 - 11:47am
Gene's picture
Gene says:

This study compares players of all eras, and adjusts their home run totals to compensate for level of talent, home field advantage (or disadvantage), etc. Ruth comes out way on top, and Bonds is still behind Aaron.

posted on Thu, 08/16/2007 - 10:07am
Luke Bond's picture
Luke Bond says:

i think that bonds should not have beat Hank Aaron because bonds was on steroids if he was not on steroids he would have still come close our beating Hank Aaron. But I think A-rod will beat both bonds and Aaron. A-rod rocks!!!!

posted on Thu, 08/16/2007 - 4:04pm
bbdude's picture
bbdude says:

Aaron worked hard without STEROIDS (unlike BONDS)

posted on Thu, 08/16/2007 - 4:04pm
A-Tau's picture
A-Tau says:

A-Rod did take steroids. I believe that steroids do not have an impact on how many homeruns someone can hit. A-Rod was said to have taken steroids from 01-03. He just hit his 600th homerun this year (2010).

posted on Tue, 08/17/2010 - 11:17am

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