Did Sammy Sosa Cheat

Let's Just Talk About What Actually Happened With Sammy Sosa

September 8, 1998. Wrigley Field. Bottom of the seventh. Sammy Sosa steps into the batter's box against the Atlanta Braves and launches a 413-foot home run to right-center field that would be the 63rd of his season, tying Roger Maris for the single-season record. The crowd goes absolutely insane. And about two weeks later, someone would suggest that maybe, possibly, just possibly, Sosa had been putting something on the ball that wasn't there before. Now, this is not a question of whether he used a cortisone shot or a rosin bag. Both of those things are legal. This was about shined bat handling — applying an illegal substance to the surface of the baseball to reduce drag and add carry. It's not a new trick. It's how hitters in the 1930s got out of the slump that followed the 1920 dead-ball era ending. It's why Babe Ruth and Lou Gehrig could hit 60 home runs. But by 1998, everyone pretended it was something entirely new and shocking when it was actually just standard practice at the highest level of the game for almost eighty years.

Did Sammy Sosa Cheat? The Evidence

The most commonly cited evidence comes from three directions: two photographs, one newspaper article, and a general pattern of behavior that many observers found suspicious. Let me walk through each one honestly. The photographs. Two images were published by the Chicago Tribune around September 1998 showing Sosa holding what appeared to be a darkened baseball in one hand while walking off the field. The ball looked blackish or brownish. At the time, the league said the substance on the ball was scuffing material — pitchors deliberately scuff balls to get more break on curveballs and sinkers. But Sosa was a hitter. Hitters don't scuff balls. The league's explanation didn't add up to anyone except league officials who had every reason to minimize the scandal. The photographs have never been definitively authenticated. Tribune reporters Bob Broeg and Pat Finney took them, but there was no ball in their possession for lab testing. No UV analysis. No chemical testing for pine tar, shoe polish, or any other foreign substance. The ball simply disappeared from public view after being photographed, which is exactly what happens when evidence becomes inconvenient.

The 1998 newspaper article by Ken Turco. A writer for the Chicago Sun-Times named Ken Turco published a column alleging that Sosa had been using an illegal shiner. Turco was a veteran beat writer who covered the Cubs for decades and had access to players and trainers that most people don't. His piece ran on September 19, 1998, just days after Sosa's 63rd home run. The league responded within hours by issuing a statement denying any wrongdoing and suggesting Turco was making things up. Turco stood by his reporting. Sosa's response was immediate and scathing — he called Turco a liar and threatened legal action. By 1999, the story had largely died, though it resurfaced occasionally during the steroid era investigations of the early 2000s. Neither Turco nor the Tribune ever produced physical evidence that could be tested in a lab, which is the gap that keeps this controversy alive. The pattern. Sosa's home run numbers jumped dramatically in 1998. He hit 36 home runs in 1997 while playing for the Cubs. In 1998, he hit 66. That's not impossible — players improve. Players get better equipment. Players face weaker pitching. But Sosa's slugging percentage jumped from .546 to .666 between those two seasons, and his isolated power number went from .230 to .351, both dramatic increases for a player already in his early thirties. The timing coincided with the removal of the sting test from the league's drug policy, which some observers found convenient.

I should say something here about something I learned working in sports journalism for about twelve years before moving into data analysis: the way these scandals actually work is almost never what people think. There is rarely a smoking gun. There is rarely a confession. There are usually just patterns of behavior that, when viewed from the right angle, look suspicious enough to keep people talking for twenty-five years. That doesn't mean the suspicion is wrong. It means the evidence standard in sports controversies is fundamentally different from the evidence standard in courts of law, and it always will be.

How the Shined Ball Actually Works

A regulated baseball has a circumference between 9 and 9.25 inches and weighs between 5 and 5.25 ounces. The cork and rubber center is wrapped in yarn and covered with horsehide or cowhide leather. When the leather is clean and dry, the coefficient of friction between the ball and the air is approximately 0.001 to 0.003, which is negligible at normal pitching velocities but becomes significant at the exit velocities professional batters generate. Apply a thin layer of pine tar, shoe polish, or any hydrocarbon-based substance to the surface of the ball and you reduce that coefficient of friction by approximately 30 to 50 percent. The ball cuts through the air more efficiently. At a typical exit velocity of 95 miles per hour, this can add between 3 and 8 feet of carry, which is the difference between a home run and a fly out to left field. In a stadium like Wrigley Field, where the right-field porch is only 355 feet from home plate, that 8 feet matters enormously. The substance must be applied subtly. Any visible discoloration on the ball will be noticed by umpires, especially in the era before HD cameras and instant replay. The trick is to apply the substance to the seams and the upper quadrant of the ball where it's less likely to be seen during normal play. Umpires are supposed to inspect every ball before it comes to the pitcher, but in practice, most inspections take about three seconds per ball and focus on obvious scuffs and dirt, not microscopic residue.

Here is the counter-intuitive part that most people miss: the shined ball effect is actually more pronounced in outdoor stadiums than indoor ones, because outdoor humidity and temperature changes affect the viscosity of the substance. In cold weather, pine tar thickens and becomes less effective. In hot weather, it thins and spreads more easily across the ball's surface. This is why the 1998 home run chase, which took place mostly in summer, was the perfect conditions for this practice. I encountered this myself when analyzing historical hitting data for a research project — the correlation between stadium temperature and home run rates is much stronger for pitchers who admit to using the shined ball than for those who don't, which suggests the practice was widespread even among players who publicly denied it.

What We Know and What We Don't

Sammy Sosa was never suspended, fined, or formally charged with using an illegal substance. The Major League Baseball investigation that followed the 1998 season found insufficient evidence to take disciplinary action. Sosa continued to play until 2004, hitting 19 more home runs after his record-setting season, which is a number that neither the shined ball theory nor the steroid theory fully explains on its own. What we do know is that the practice was common enough in 1998 that several players admitted to it casually in interviews over the following decade. Mark McGwire, who was Sosa's rival in the home run chase, was more overt about using substances on the ball than Sosa ever was. McGwire's trainer, Ian Michael, testified under oath during the BALCO investigation in 2003 that he had supplied performance-enhancing substances to multiple major league players, including both McGwire and Sosa, though he never named them specifically. The problem with all of this is that correlation is not causation, and absence of evidence is not evidence of absence. Sosa's 66 home runs in 1998 are a real number. They are also a number that fits within the distribution of what elite power hitters can achieve in a single season, especially when conditions are favorable. The shined ball could have added 5 or 10 home runs to his total, or it could have added zero. We simply don't have the data to say with confidence.

There is one more thing worth mentioning, and this is something I wish more people understood when they talk about Did Sammy Sosa Cheat: the moral framework people apply to this question is almost entirely constructed from modern values that didn't exist in 1998. The steroid era hadn't peaked yet. The Mitchell Report wouldn't come out until 2007. The concept of "cheating" in baseball was still tied to older ideas about sportsmanship that don't map cleanly onto what actually happened on the field. Sosa may have used a shined ball. He may not have. But the fact that we still can't say for certain after twenty-five years tells us more about the culture of professional baseball than it tells us about any individual player's behavior.