How Cody Bellinger is currently the best player in baseball

The 2019 season has been kind to Cody Bellinger. He’s arguably the best player in baseball right now, at least offensively. With over one hundred plate appearances under his belt this season, moderate conclusions can be made. This year Bellinger has improved in almost every statcast category. Average exit velocity, average launch angle, and barrel% are all up just to name a few. When all of those numbers are graphed, a common theme is seen. From his first year in 2017, his historic rookie season, he came on to the scene as a superstar. He regressed a little bit in 2018, which is expected. It’s very difficult to maintain such a high level of playing ability in baseball. Except for this season he has jumped back up to MVP level. Take a look below at the xwOBA leader board across all of baseball.

Info via Baseball Savant

Bellinger sits in a distant first place compared to the rest of the league. I know that Howie Kendrick is in second right now which definitely won’t continue for long but you can’t ignore Bellinger’s success. Take notice that the player’s whom you wouldn’t expect to be in the top 20 of xwOBA have fewer at-bats than most of the players on the leaderboard. As time progresses, their stat lines will regress back to their expected performance. However, for Bellinger, that may not be the case. He’s outperforming Mike Trout, who is commonly known as the best player in baseball. It’s not even like he’s just barely outperforming him, he is leaps above him right now. This will not be sustainable over the course of the season, but for now, it’s exciting.

As I searched for a reason behind his newfound success, I did find an answer. Obviously, the most basic reason would be his increase in exit velocity, launch angle, and barrel% in addition to so many other statcast measurements. What I found was the reason behind what’s making those numbers go up. There is one simple variable that is pushing all of the others up. Simply put, no one is throwing him strikes. If you take a look below, his in-zone% has gone down and his out-zone% has gone up.

These changes aren’t small either. These are some very significant changes. For the first two years, there isn’t any sort of a dramatic change between the numbers. You can see that this year has been an outlier so far. There has been almost a five percent change each way as they add up to a full one hundred percent. Pitchers are throwing him fewer strikes and by result, he’s posting extraordinary numbers.

This theory that I developed can, however, go both ways. In opposition to my argument, you can argue that these numbers are changing because of his performance. You could say that because he is putting up such stagnating numbers, pitchers are then throwing him fewer strikes. This viewpoint is definitely a valid rebuttal but I don’t see it to be correct.

As I have stated, Bellinger is finding such great success because pitchers are throwing him fewer strikes. There are many more reasons that back up this viewpoint than the one that I stated in the previous paragraph. In the following paragraphs, I am going to walk you through each of them.

Reason 1: When pitchers throw a lower amount of strikes, it puts Bellinger in favorable counts, and when you’re put into favorable counts you tend to succeed. Now, there isn’t exactly a way that I can measure this, but logically it makes sense. When pitchers don’t throw you strikes, they eventually force themselves to throw strikes. When you “force” a strike, you are more likely to make a bad pitch. Just think, if a hitter often faces 3-1 counts, he’s going to hit pretty well.

Reason 2: In addition to fewer strikes being thrown, his plate discipline has increased. His chase% has taken a huge dip, as you can see below. This is a huge change too, just like the changes in his in zone% and out zone%. So you can see that in addition to Bellinger facing fewer strikes, he also doesn’t swing at as many pitches outside of the strike zone. Both factors are big factors towards posting quality numbers at the plate.

After evaluating his statcast numbers, I was curious as to if he made any mechanical changes that may have lead to his new found success. As it turns out, he did. Bellinger used to stand completely straight up at the plate with his hands positioned high. Now he has lowered his stance as well as his hand position. Below is a picture from each season and you can see the changes that he made. On the left is an image from 2018 and on the right is from this season.

2018 vs 2019

As I compared swings from the two different seasons, there was one other big change that I noticed. The change was in weight transfer. In 2019 Bellinger appears to be doing a better job at keeping his weight back. Last year when Bellinger would swing, his front knee would come towards the ball after his stride. Now his front knee stays back after his stride showing that he is able to keep his weight back. The viewpoints seen below are from different angles but you can clearly see the major difference in weight differentiation between the two seasons.

2018 vs 2019

This would definitely be a reason as to why he has been able to see such a big increase in exit velocity this year. His line drive% is also up, while his fly ball% and ground ball% are down. All indications show that he is driving the ball much better this year. These mechanical adjustments along with the fact of pitchers not throwing him strikes are what have contributed to Bellinger being the best player in all of baseball so far this year. He may not be the best by the end of the year, because of Mike Trout, but for now, Cody Bellinger is the best player in baseball, offensively.