One of the advanced stats that you hear most often referred to these days is one called Wins Above Replacement, which is commonly abbreviated as WAR.

I have spent a fair amount of time trying to understand and appreciate this stat. Many of the podcasts, articles, and books I read regularly rely heavily on this stat in their review of player performance.

I am told it is currently one of the best tools we have (if not the best). But try as I might, I cannot really understand or appreciate it.

Here is the page from MLB.com that tries to define and explain WAR.

Wins Above Replacement (WAR)

Definition
WAR measures a player’s value in all facets of the game by deciphering how many more wins he’s worth than a replacement-level player at his same position (e.g., a Minor League replacement or a readily available fill-in free agent).
For example, if a shortstop and a first baseman offer the same overall production (on offense, defense and the basepaths), the shortstop will have a better WAR because his position sees a lower level of production from replacement-level players.

The formula
For position players: (The number of runs above average a player is worth in his batting, baserunning and fielding + adjustment for position + adjustment for league + the number of runs provided by a replacement-level player) / runs per win
For pitchers: Different WAR computations use either RA9 or FIP. Those numbers are adjusted for league and ballpark. Then, using league averages, it is determined how many wins a pitcher was worth based on those numbers and his innings pitched total.
Note: fWAR refers to Fangraphs’ calculation of WAR. bWAR or rWAR refer to Baseball-Reference’s calculation. And WARP refers to Baseball Prospectus’ statistic “Wins Above Replacement Player.” The calculations differ slightly — for instance, fWAR uses FIP in determining pitcher WAR, while bWAR uses RA9. But all three stats answer the same question: How valuable is a player in comparison to replacement level?

Why it’s useful
WAR quantifies each player’s value in terms of a specific numbers of wins. And because WAR factors in a positional adjustment, it is well suited for comparing players who man different defensive positions.

Now the first thing you will notice is that different sites have different ways of calculating WAR. The basic idea remains the same however: how does an individual player compare positively or negatively against the stats of an “average” replacement player just called up from the minors.

Once you begin to grasp this basic idea of a “replacement player”the first question that may come to your mind (if you are not a data-first-kind-of-person) is, “are you really comparing this real-life, Big League shortstop or to some mythical player getting called up from some mythical AAA league and playing with real life players at the other positions?”

The more I have tried to understand this concept of a data-determined replacement player the further it eludes me;

• What are the names of these replacement players? Do they have cool nicknames?
• Can I get their baseball cards?
• Are they left or right handed? Or are they switch hitters?
• Do they like the ball down in the strike zone? Do they prefer one kind of bat over another?
• When they are in the dugout are they good clubhouse guys? Do they take extra BP? Do they wear their socks up to their knees or do they prefer the full-pants look?
• If they are pitchers, what is their best pitch? What if the replacement is a knuckleballer? How does that change the equation?
• Where did they grow up? (some baseball people like Keith Hernandez think that players from northern climes like Minnesota mature later as players.)
• Are they from Puerto Rico or the Dominican Republic? Are they converted shortstops? Or converted pitchers? Do they need a translator?
• Are they streaky hitters? Do they like to take the first pitch?
• How well do they pitch from the stretch? What is their move like to first base?

Alas, my poor poet-mind cannot make peace with the idea of WAR. But do your own research. A lot of baseball people put a lot of stock into the idea of WAR. And they get paid to give their opinions about baseball. And since my opinions are free, my opinion is probably worth exactly what you are paying for them.