The Dwindling Chances of Seeing a Triple

The game before us is forever changing, because it has to be. Even when there aren’t abrupt changes in rules or dimensions or make of the baseball, there are changes in strategies and changes in the player pool. Those changes that do take place tend to be subtle, gradual, and we’re all well aware of certain league-wide trends.

We know that strikeouts are higher than they’ve ever been. This past season, the strikeout rate also rose just one-tenth of one percentage point. We know that we’re seeing a little less bunting these days, and we know that offense is down relative to what it was in what many choose to refer to as the Steroid Era. We know that, for whatever reason, there are more hard-throwing pitchers, coming out of seemingly every bullpen and sometimes even starting games. Fewer people might be aware of the trend with triples. And fewer still might be aware of what just happened in 2013.

It’s not new news that triples have declined in frequency over time, especially relative to the early 20th century. Here’s John Walsh on the subject from May 2006. Here’s Dan Fox from January 2007. In 1915, there were almost a thousand more triples than there were in 2013, in three-quarters as many plate appearances. The game is just completely different from what it was a hundred years ago. But still, I want you to look at a chart, because this is about the big picture and the little picture. I took all the data from FanGraphs and looked only at numbers for non-pitchers, league-wide, for the sake of giving modern-day baseball a break.

What that shows, at first glance, is the opposite of a decline, but that’s why we give more than single glances. This is plate appearances per triple, league-wide, since 1900, and even before last year, triples became relatively rare as offense boomed. Then last year set a new record, at 235 plate appearances per three-bagger. That was up from the previous year’s 194. There were an average of 2.5 triples per 600 plate appearances, dropped from the previous record low of 2.9. Never before has a triple been so very uncommon.

Another way of looking at this: last year, non-pitchers hit 762 triples. Before that, the lowest triple year was 2010. Applying 2010’s rate to last year’s number of plate appearances yields 862 triples, higher by exactly 100. It’s not just that triples are on the decline, and have been for a while; it’s that, last year, they declined sharply. More sharply than pretty much ever.

Year-to-year, last season’s triple rate fell 18%. That hadn’t happened since triples fell 20% between 1901-1902. Triples fell 11% in 1986, and 12% in 1978, but they rose 11% in 1977 so that could’ve just been evening out. And those numbers don’t really compare to 18% anyway, aside from being in the double digits. Those who believe the triple is the most exciting play in baseball are wrong, and they were also just left particularly dissatisfied. Tough going for those folks, save for the part where they’re blessed to be able to pay attention to baseball in the first place.

I don’t know how to explain last year’s decline, but it happened. I also don’t know what it’s going to mean going forward, but it’s not like the trend itself is going to stop. In the big picture, there are reasons for the decline. There are home runs now, for one thing. Stadium dimensions have changed. Players are built differently, and selected differently, and there’s less overall variation in talent. But not that much has changed in the last 20 years or so. Certainly, not that much changed between 2012 and 2013. Triple rates have been fairly stable since the start of the Steroid Era, but now we have to wonder if last season signals a new adjustment. Was it a blip, or an indication of our new reality?

Intuitively, we can make some sense of it being real. Or, we can make some sense of triples continuing to dwindle. There’s better information than ever, now, about where hitters hit the ball. There’s greater openness than ever, now, to experimenting with defensive alignments. There’s a lot of emphasis put on player defense, and every year brings improvements in defensive evaluation. And there’s the mathematical reality that triples have an average break-even rate around 80%, when you’re thinking about stretching from second. That hasn’t really changed, but teams now are increasingly guided by the numbers, and coaches will probably err more toward being conservative. Basically, there are things teams can do defensively to reduce the likelihood of a triple, but there aren’t many things teams can do offensively to hit more balls hard away from where the outfielders are. Runners could try to take more chances, but it’s not like triples are the end goal.

As it happens, last year also saw the lowest double rate since the strike-shortened 1995. The overall double/triple rate was the lowest since 1993. I have to believe that outfielders are getting better, and better positioned. We haven’t been observing real changes in BABIP, but all hits aren’t created alike. Relative to other kinds of hits, singles have gone up.

Triples, obviously, are never going away entirely, especially as long as Coors Field is a thing with a baseball team in it. But they’ve become less and less frequent, and there’s reason to believe that’ll continue into the future, and while you might think Billy Hamilton could save the three-bagger, he hit just four of them last year in Triple-A so even that’s far from certain. With fewer balls in play in general and better defensive abilities and alignments in the field, it stands to reason triples will be a rarity. It’s a change you’ll never notice on a game-by-game basis, but then, that’s the way it usually is.