Extra Rates

I was curious to see if triples were continuing to disappear from the game, but thought it would be good to look at the rates of all three types of extra-base hits over time. This spreadsheet contains a graph of extra-base hit rates per game since 1957 (the period covered by the Day by Day Database). The moving average is based on four seasons.

First, triples do continue to disappear. After making a comeback in the 1970s, triples have declined in every decade since. Triples are comparable to one-run strategies like stealing bases or bunting to move runners. Taking an extra base is worth the risk of an out when runs are scarce.

Note that doubles and home runs tend to move in tandem, although from season to season, home runs tend to spike more than doubles. During the 1980s, for example, the doubles tend is fairly flat while the home run trend shows a nice hump.

Note two that the end of the PED era* saw a shift from home runs to doubles, as the two-base hit took longer to go into decline. Maybe balls that would have cleared the fence earlier became wall scrapers.

*That is a convenient name for the era. There were trends in ballpark construction, valuing hitters over pitchers, maybe even changes in the baseball that contributed to the rise in home runs.

Right now, the double rate is not really following the big spike in the home run rate. Players are hitting more doubles, but not a lot more doubles. Home runs blew past the 2000 season peak, while doubles have not approached the 2007 peak.

from baseballmusings.com http://ift.tt/2zPE3hc