So far we have covered different hitting and pitching statistics. Today, we will be learning about some stats that can be used for evaluating hitters AND pitchers. I think FanGraphs does a great job giving a simple breakdown of the different plate discipline statistics. Here is a link to the page in case you want to see more for yourself.
As you can see, any stat that starts with an "O" means outside of the strike zone and any stat starting with a "Z" stands for in the strike zone. All of the plate discipline numbers are presented as percentages. To help explain these numbers, let's look at some numbers from Cubs players in the 2019 season.
These are the nine Cubs hitters who had +250 PA's. Hopefully these numbers, more so than other stats we have looked into, compare with what your eyes tell you when watching a Cubs game.
Javy Baez LOVES to swing. Our eyes tell us that, and guess what? The plate discipline stats show us that as well. His O-Swing% (outside the zone swinging percentage) is 44.1%, which led the team. His Z-Swing% (in the zone swinging percentage) of 74.3% also led the team. Both of those stats translated to Javy swinging at a pitch 55.2% of the time (Swing%) again leading the team. Players don't usually succeed in baseball with these kinds of numbers but Javy is El Mago and he makes it work. Javy has the lowest contact percentage on the team but when Javy hits it, he usually hits for extra bases (.250 ISO in 2019), and that's what helps make him an above average hitter.
And now let's look at the Cubs starting pitching from 2019 who will still be in the rotation come April.
All four of the Cubs starting pitcher have similar plate discipline numbers. We can see that Kyle Hendricks started off 66.4% of plate appearances with a strike (F-Strike%) and Yu led the staff with a swinging strike percentage of 13.4% (SwStr%). Generally you want pitchers to have higher O-Swing% because that leads to more strikeouts, or if a hitter does make contact it is usually weaker contact like a popup or a ground ball.
When it comes to hitters, there are no magic percentages that let you know if a hitter is an above average hitter or not. Look at any of those Cubs hitters and they are all above average last year (except Almora) and you see they all have success doing things differently. The exact same thing can be said about pitchers. So what do we do with this information?
Next week we will be looking into the quality of contact stats and use those with what we have learned today to further evaluate a player.