Today we will finally dive into the stat that encompasses all other stats. A stat that allows you to compare players from other positions, across different seasons, and each other's careers. WAR, otherwise known as Wins Above Replacement, analyzes every aspect of a player's game and spits it out in a single number. Now WAR is calculated differently for pitchers and position players so today we will just focus on the latter. Let's start with the calculation.
There is a bunch of different components that go into WAR so let's do a quick breakdown of each element. Batting Runs is calculated using things like wOBA and wRC, and converts it into a single value. Base Running Runs takes a look at a player's stolen bases and caught stealing number (amongst others) and turns it into a single value. Fielding Runs uses UZR to calculate how many runs a position player helped or hurt his team. League Adjustment balances out the different run scoring environments between the NL and AL. Replacement Runs is calculated to try and find what the value of a minor league player would be or a really poor MLB bench player. Essentially if the Cubs lost Rizzo at first base and had to replace him with a minor league player, how much value did the Cubs lose. All of those are divided by Runs Per Win, usually somewhere between 9 to 10 runs.
The one element I did not mention is the Positional Adjustment value. Not all positions are created equally on the defense scale. A catcher is more important defensively than a left fielder and the shortstop position is more important than second base. Below is how the positional adjustment is broken down.
It should be noted that if a player has played multiple positions throughout the season, his numbers are individually calculated per position. A more complete breakdown of the different elements can be found here at Fan Graphs. Also, Fan Graphs and Baseball Reference calculate their versions of WAR a tiny bit differently. I normally use Fan Graphs but some people like Baseball Reference instead. To differentiate between the two, you may see fWAR or bWAR to let you know which one the writer is referring to.
Okay Steve, so what? Well, like many of the other stats, you want positive WAR and the higher the number, the better season you had. At a bare minimum I expect a useful position player to put up a 1.0 WAR season. An average MLB player will typically be in the 2-3 WAR range. Players who post 4-6 WAR in a season are above average players and those are they type of guys you expect to be near or around the top of All-Star selections. Guys who post seasons with 6-8 WAR are going to be in-line for MVP conversations (when Kris Bryant won in 2016 he posted 7.9 fWAR). Anytime a player post 9+ WAR in a single season then you are seeing a player have a truly special season. Like one of the best ever in baseball (Mike Trout does this A LOT).
Here is how the 2019 Cubs position players did with 100+ plate appearances.
We see that Kris, Javy, and Rizzo all had very good seasons. Castellanos also had a good half season with the Cubs. Everyone from Willson down to Caratini had good to average seasons. Almora and Descalso really did not help the team but it's interesting to see how Descalso was just a bit worse than Almora even with only half the playing time that Almora had. Hopefully Almora will have a bounce back year as he fights for the center field job with Ian Happ.
Next week we will look at the pitching side of WAR and see how the Cubs pitchers favored.