Did you know that baseball batters were never taller than they were in 2006? This chart show average height weighted by plate appearances. So the more a player bats during a season, the more his height counts in the average. Click on the chart for a larger view.

As you can see by the trendline, the growth in height of hitters leveled off starting around 1987. It's still growing, but very slowly. In 2006, hitters averaged 72.8 inches. I was curious if the growth of players had anything to do with the explosion in hit by pitch numbers, but they've skyrocketed while heights leveled. It's also interesting to note that during two eras of HBP falloff, height of batters increased along the trendline.