Look, I'm not condoning it and I join you all in questioning the morality of cheaters...but I really don't think the use of banned substances requires that asterisks begin populating the MLB record book. It seems that those screaming loudest about this issue are trying to protect something as inconsequential as statistics. Not the game, not the players, their concern is for the statistics. Particularly acute screaming has been heard in reference to hitting statistics, especially the hallowed records for home runs hit in a season and in a lifetime. As I will argue below, the statistics are probably only minimally influenced, if at all, by the recent era of increased steroid use in MLB.
If you've ever tried to hit a baseball thrown by an athlete who intends to make you miss it, then you know that "raw strength" is way, way down on the list of physical characteristics needed for success. In fact, physical characteristics as a group are surely subordinate to intellectual characteristics required for success. For example, it takes carefully honed judgment to learn the strike zone and stone-cold discipline to obey that judgment in the heat of competition. It also takes snap-cognitive reflexes to estimate the velocity of the pitch, which may be quite different from the velocity of the previous pitch thrown, and to make the necessary timing adjustment to begin a swing. If the proper timing can be instantly deduced, a hitter still needs lightning-quick decisiveness to determine if the pitch will arrive in a hittable location. Furthermore, a cultivated ability to discern one pitch from another based on a pitcher's motion and/or release point and/or the spin on the ball is primal in hitting success and surely benefits hitters more than any physical characteristics I could name.
Also in the non-physical realm, let's consider psychology, mental toughness, and what I will call "baseball intellect" as it pertains to why one tries to hit the ball in the first place.
First, psychology: Hitting is largely a confrontation between a pitcher and a hitter. There is an element of history between the two stemming from previous at bats and who "won" those encounters. Both parties rely on that history to inform themselves and seek advantages against the other. Each is aware of what the other may have learned last time around and a silent chess match unfolds across the pitches of every at bat. Hitters try to own the plate by crowding close to ensure that they can hit a ball on the outside corner. Pitchers try to reclaim turf by throwing inside and moving the batter back in the box. The psychological victor is heavily favored to win the physical battle and, as far as I know, steroids confer no psychological advantages.
Consider mental toughness: Given the enormity of the competitive pressure under which MLB hitters often find themselves playing, the intellectual challenges described thus far are commonly exacerbated by the emotions of the moment. To remain calm, to concentrate, and to focus one's intellect on the physical task at hand, despite the swirling emotions, the energy of the crowd, and the tension of the competition, requires a confidence and a state of mind that steroids really cannot facilitate. In fact, the scant evidence available suggests that steroids might attenuate mental focus in favor of emotional intensity which would theoretically serve to reduce hitting efficiency.
And finally, baseball intellect: There is a lot to think about during an at-bat and the hitter with acumen for distilling the nuances of the game is advantaged. The contemplative hitter benefits when he knows the pitcher's "go to" pitch and can anticipate the pitch, velocity, and/or location that the pitcher favors in certain circumstances. Furthermore, knowing the game situation is important. For example, if there is a runner on third base, the pitcher may be less inclined to throw low and may resist throwing a breaking pitch to reduce the possibility of a passed ball that would allow the runner to score. Using such knowledge demands that the hitter know and process the score of the game and the stage of the game in order to make a judgment about if such a run would be important enough to influence pitch selection or location. He must also consider who bats next and what kind of success that hitter has had against this pitcher (and against any pitcher who might be called in for relief) as all of this information will greatly influence the likelihood of seeing pitches in the strike zone versus seeing less hittable pitches that might culminate in a walk. In this example, he must also know and process the speed of the runner on 3rd base, the depth of the backstop, and the mobility of the catcher to properly calculate the likelihood of that runner influencing pitch location. Clearly, there is a lot to consider in addition to hitting the ball. It is the hitter who can process this multitude of information and draw a likely conclusion (during the brief moment between two pitches) who will step back into the batter's box with a distinct advantage against the pitcher. Such advantages are not likely derived from abusing banned substances.
If one has the intellect and processing speed for making good swing decisions, the psychological dexterity to spar and win against a crafty pitcher, the mental toughness to tune out the distractions and master the moment, and the baseball intellect to anticipate the probable tendencies of his opponents, then we may begin to consider the physical characteristics of good hitters. But don't kid yourself, even among the physical characteristics that abide successful hitting, it is the non "strength-based" skills such as hand-eye coordination, timing, and flexibility that serve a hitter more faithfully than power.
Alas, if the majority of the disparity between good and bad hitters is explained by the characteristics above, some small portion is certainly attributable to strength. There is no doubt that steroids can help hitters gain strength. Of course, steroid use may also lead to unnatural development of those muscles specifically taxed in weight training and to strength imbalances across muscle groups. This is a recipe for injury and injuries tend to hamper on-field performance and suppress the accumulation of gaudy statistics.
I know what you're thinking....home run statistics went through the roof exactly when steroid use appears to have become more prevalent. The hallowed records fell! What's more, the numbers have diminished in the face of tighter drug testing by the league. Both thoughts are commonly reported, both are untrue. Yes, the records fell; no, the statistics did not go through the roof; no, home run hitting has not declined in the face of drug testing. A look at the data clearly shows that the number of home runs per at bat has been flat for forty years. A few hitters have pushed single season records upward but this may have more to do with economics than with physics. A salary premium has come into effect for home run hitters, which probably has players swinging for the fences more often in a bid to earn higher pay. This plausible explanation is supported by the facts that strike-outs per at-bat have risen dramatically even though the strike zone has shrunk in the recent era. The economics of the game have shifted the focus from “contact hitting” to “power hitting” and the most gifted sluggers have set new records.
Also, let's not forget about our old friend "multi-colinearity" who would suggest that another coincident development that most probably aided the power hitters in their home run campaigns is weight training. It is well documented that widespread weight training, even in the off-season, first became common during the period in question. The conventional wisdom had always been that baseball required flexibility, speed, coordination, and other physical attributes that might be diminished by bulky muscle mass. The home run kings of my childhood, (those whose records are now being fiercely protected by aforementioned screamers), did not lift weights. Presumably, they didn't take steroids either. The point is, weight training and steroids came to town at the same time and new home run records were set shortly thereafter. Naming steroids as the driving factor in the new records requires an unscientific leap.
Last but not least, let us bear in mind that raw strength also favors pitchers and many of the alleged abusers have been pitchers. I concede that steroid based strength has probably helped some hitters hit more home runs but probably not as much as better weight training programs have helped. Furthermore, these hitters have performed against juiced pitching. I invite any body-builder with bulging, steroid-fueled muscles to step into the batters box and see if he can even make a good decision to swing or not. Every major league player has the strength to hit a home run. In fact, I suspect that most grown men, be they accountants or auto mechanics, probably have the strength to hit a baseball out of a major league park -- it really is not about strength. The greatest home run hitters are usually strong but they are smart first, talented second, and strong last.