That remaining chunk of the drop in scoring may be caused by some combination of factors affecting hitters themselves. Fewer walks were issued, so we see lower OBPs across the board. This is usually assumed to be caused by either the pitchers or the umpires. There is no real change in BABIP, which hitters are usually given a significant amount of credit for. But we do see a drop in batting average across the board of about 0.007. Part of that comes from the rise in strikeouts, but part of it comes from a power outage. The average AL team in 2010 hit 20 fewer home runs than in 2009, despite hitting more fly balls! For Major League Baseball as a whole, the total number of hits fell by 2.23% year-on-year. However, singles fell by only 0.72%, doubles by 2.87%, triples by 8.75% and home runs by 8.51%. Again, this isn’t caused by more balls being hit on the ground – there were more fly balls hit in 2010 than in 2009 even when pop-ups are excluded.
It appears that a large number of balls that were being hit over outfielders heads in 2009 were catchable balls in 2010. Exactly what it is that has caused it remains a bit of a mystery. Is it luck? If this had happened to one single individual, I would certainly argue yes, but for the whole sport? It’s a bit of a stretch to argue that this has anything to do with the end of the steroid era in baseball. Scoring (and power) was down already from 2007-2009 relative to, for example, 2001. The testing regime for steroids hasn’t changed, and there is still no test for HGH. If we’re looking for what caused the drop in power from 2009 to 2010 specifically then that can’t be the cause. The argument could be made that better pitching has led to fewer hard-hit fly balls, and that is leading to fewer extra base hits. Still, home run to fly ball ratio (again, excluding pop-ups) doesn’t seem to be something pitchers have a tremendous amount of control over. It may really be the case that changes in balls (allegedly somewhat softer than a decade ago) and particularly bats, redesigned without much fanfare to reduce the risk of fan injury from breakage, are causing balls to fly just a little less far when you hit it right on the sweet spot.
There may be some luck component to all of this, so expecting a bit of a ‘regression to the mean’ in 2011 isn’t silly. That part of it caused by different bats and better methods of protecting pitchers’ health will likely continue on into the future, and I do feel that it’s a good thing for baseball. We have seen an unusual number of perfect games, no-hitters, etc… lately – but we haven’t seen teams (other than the Seattle Mariners) shut out again and again. Lower scoring should mean more tight games, especially if we’re seeing fewer pitchers that don’t belong in the show getting shelled. Pitcher injuries can turn fan optimism to despair overnight. And as much as I enjoy seeing home runs, that doesn’t compare to the distress I feel when a fan gets shards of bat in the eye – assuming that really is what’s going on.