Clint Hurdle frequently discusses the importance of hitters "staying stubborn with their approach." Over the course of the opening homestand he outlined three elements of approach, which he said the team worked on extensively during Spring Training:
- Plate discipline: i.e. not swinging at pitches out of the strike zone.
- Hitting the curveball: Hurdle said they "lit up" the pitching machine during spring training, taking "more reps than we've ever done before; more swings than we've ever done before [against the curveball]."
- Driving the ball to all fields: a skill of added importance with more teams aggressively employing defensive shifts.
Obviously, the Pirates are not unique in stressing these three aspects of hitting. However, since Hurdle mentions them fairly frequently, and because they were areas of particular weakness in 2013, it is worth monitoring the Pirates' efforts to improve their approach this season.
Before looking at the numbers, here is the obligatory caveat about small sample sizes: We should not make too much of what appears to be the improved approach of Pirates' hitters this early in the season. It is likely that the numbers will change dramatically over the course of the next few months. This, then, is merely an early snapshot of what will be one of the important storylines this season.
There are many ways to measure plate discipline, but here I'm going to focus on the one that I find most compelling: O-Zone percentage.
O-Zone percentage is the percentage times that a hitter swings at pitches outside of the strike zone.
The Pirates are swinging at 5.5 percent less pitches out of the strike zone over the first eight games of the season, and rank in the top sixth of the MLB. Interestingly, the league O-Zone rate is down 2.2 percent.
A number of important contributors to the Pirates' offense are displaying better discipline. But it's early!
To see how well the Pirates are hitting the curve, I used Fangraphs' pitch linear weight values. The pitch value indicates the number of runs above or below average the team is producing against the pitch.
Here again we see that the Pirates have shown solid improvement in their approach against the curveball through the first eight games.
The players showing some of the most improvement so far are Starling Marte, from -.9-to 1.5, and Pedro Alvarez, -4.1-to .4.
Hitting the ball to all fields
In order to examine the distribution of batted balls, I calculated the percentage of balls pulled, hit up the middle and hit to the opposite field. Horizontally the Pirates are compared to league average; vertically the Pirates are compared by season.
(Click to enlarge)
The Pirates are pulling the ball less, hitting the ball up the middle more and hitting to the opposite field slightly less. Overall, while they are not hitting the ball to the opposite field more, they are pulling less, which one could say is an improvement over excessive pulling.
They are still hitting the ball to the opposite field less than MLB average, but they make up for that difference by pulling less, and hitting it up the middle more.
It is so early in the season that I feel a little uncomfortable posting a study like this. However, the Pirates' hitting approach is already becoming a storyline, and it seems to be showing signs of improvement over last year. I am sure that we will revisit this issue throughout the season.