After some extensive research in April 2013, I found that one of the reasons why pitchers are starting to dominate baseball is because first pitch strikes are up and first pitch swing rate are down league wide.
These graphs from fangraphs.com showed how first pitch strikes were up and first pitch swing rate was down over the last few decades.
In 2013, there was a slight uptick in the league wide first pitch swing rate at 27.1 percent. It’s higher than 2012, but still significantly lower than the figures from the 1990s and early 2000s.
Meanwhile, first pitch strike rate continued to trend upwards and cracked 60 percent in 2013. In other words, pitchers are still noticing that hitters aren’t getting their bats off their shoulders on the first pitch so they’re throwing it over the plate. A higher first pitch strike rate is probably somewhat responsible for the lowest amount of runs scored this year (4.17 runs per game) since 1992.
How much does a first pitch strike matter? A lot.
The league wide OPS for hitters is around 200 points higher after first pitch balls compared to first pitch strikes. Thus, it’s easy to see why first pitch strikes are important for pitchers. If hitters aren’t going to swing on the first pitch, it becomes easier for pitchers to get ahead and statistically improve their chances of getting outs.
Getting that first pitch strike is also important in terms of mitigating runs allowed. In 2013, there was a negative correlation between first pitch strike percentage and team ERA. This only includes strikes that were not hit into play (i.e. only 0-1 counts since a ball hit into play is technically recorded as a strike). This means that the higher a team’s first pitch strike percentage was, the lower their ERA was. In fact, the p-value for the regression was a miniscule 0.002 – well below the .05 cutoff mark for statistical significance.
So knowing this, have hitters adjusted?
The truth is, hitters have had great success when they hit the first pitch into play. The league wide average for batters when they hit it into play on the first pitch was .336 in 2013, up from .330 in 2012. Batters also hit it into play around 200 more times this year compared to 2012. So perhaps, they are adjusting a little bit and they should continue to do so, especially if the first pitch strike rate continues to rise.
That being said, hitters are taking more pitches than ever before in full plate appearances:
We’re living in an era where teams like the Red Sox live off taking the first pitch and working counts. While it seemed to be effective for the Sox this year, the idea of patience leading to more runs is a myth. There was no correlation between pitches per plate appearance and runs scored in 2012 and 2013. In 2013, the p-value in the regression between the two variables was 0.21 – not even close to statistical significance.
Patience at the plate has become somewhat of a fad. A lot of teams, including the Red Sox, have adopted the approach. (This has also led to longer games – another story for another day.) But pitchers know this and as a result, they are taking advantage of it and throwing first pitch strikes. Being patient doesn’t really put a hitter in any sort of advantage because the data shows that in recent years pitchers will throw strikes if a player doesn’t swing – thus, putting the pitcher at an advantage.
For example, the only team that took more pitches per plate appearance than the Red Sox were the Minnesota Twins and they generated 3.79 runs per game – sixth lowest in the league. Meanwhile, the Detroit Tigers took the fifth fewest pitches per plate appearance but scored the second most runs in MLB.
So what separated the Red Sox from the Twins? At the end of the day it came down to sheer talent. The Red Sox had players that knew how to hit well and the Twins didn’t. The whole philosophy of taking pitches doesn’t do much. If the Red Sox were a free-swinging team they could have been just as successful at the plate.
In fact, the Red Sox could be hurting themselves by being so patient. That may sound crazy since they had the best offense in baseball this year, but consider the following:
The Red Sox laid off 5,080 first pitches this year and 2,629 were balls. That’s only a 51.8 first pitch ball percentage – the lowest in the league. As mentioned above, hitters league wide have a higher OPS when they see a first pitch ball compared to a first pitch strike and there’s a strong correlation between pitcher’s throwing first pitch strikes and ERA. So the Red Sox are essentially putting themselves at a disadvantage by falling behind in the count so often.
The fact that the Red Sox were so successful at the plate this season is a testament to the quality of their hitters. Guys like Dustin Pedroia, Daniel Nava, Jacoby Ellsbury, and Shane Victorino all had contact rates over 83 percent. They didn’t swing much, but when they did they made it count. The four players also had swinging strike percentages that were less than 11 percent. They’re smart hitters.
What’s interesting is that the Red Sox are welcoming A.J. Pierzynski to their team this spring. Pierzynski is a free-swinger. He swung at 40 percent of first pitches last season (7th most in MLB – Pedroia only swung at 10 percent of first pitches) and took the second fewest pitches per plate appearance last year among qualified players. Whether he adapts to the team’s patient philosophy or continues to hack at every pitch remains to be seen.
To recap: Hitters continued to be patient this year – not swinging at 27 percent of first pitches. As a result, pitchers threw more first pitch strikes as 60 percent of all plate appearances started off with first pitch strikes. Because there is a strong correlation between first pitch strike percentage and ERA, pitchers have been able to mitigate offensive damage over the last few years as hitters continue to lay off the first pitch. Finally, using a patient approach at the plate does not correlate with scoring more runs. Rather, smart hitters who take good approaches at the plate and swing at the right pitches are more likely to be successful.