It may seem that the Denver Nuggets have quite the advantage when playing the Detroit Pistons. Of course, this isn't necessarily due to athletic ability, but rather, altitude.
Denver, which is high up in the Rocky Mountains, is home to much thinner air than lower locations of Colorado, or Detroit for that matter.
The higher up you go, the lower the air pressure becomes. That means that there are fewer oxygen molecules in the air, so it becomes harder to get enough oxygen when you breathe.
At sea level our blood is 99% saturated with oxygen, but at around 18,000 feet, the blood has about 30% less oxygen. This can make people like mountain climbers or hot air balloonists, who don't take proper precautions, feel nauseated, dizzy, and tired. If it gets really bad this so called altitude sickness can even kill you.
Of course, the Pistons aren't in that much danger. Denver isn't so high up above sea level that it makes most people sick. Also, professional athletes are better able than most people to adjust to higher altitudes. However, there's still less oxygen in the air, and since the Denver players are used to playing in those conditions, they have an advantage. If nothing else, the Pistons' lungs have to work harder to get enough oxygen into the bloodstream.