Think of the following 5 players from the 2019 Reds: Jose Iglesias, Derek Dietrich, Aristides Aquino, Curt Casali, and Jesse Winker. All five of them posted between 1.0 and 1.6 fWAR in 2019. With that in mind, which of these players would you say was the most productive?
Your first reaction would be to say Iglesias, who posted the 1.6 fWAR. In all reality, Iglesias was not the most productive, posting the lowest wOBA and OPS of the five, though he did provide significant defensive value.
This is because WAR is a counting stat, meaning more games and more PA will usually lead to a higher WAR. There is a simple adjustment that can be made, however, to better interpret a player’s success. Rather than looking at a player’s WAR, look at their WAR/162, or in other words, their WAR per 162 games played.
Let’s look at those same five players again, using WAR/162 rather than WAR.
When looking at WAR/162, Aristides Aquino was the most productive of the five, followed by Casali, and then Iglesias in third.
It is true that sometimes it will still be better to look at WAR on its own. For example, when looking at league leaderboards, WAR itself is probably enough. The same applies when looking at a player’s entire career. But WAR/162 can be used as a sort of tiebreaker when comparing two players with similar WAR totals, and it stands to reason that WAR/162 may be a more valuable tool for projecting a player’s future performance.
An example of this is when looking at a player that has recently had multiple injury-shortened seasons. Think of former Red Yasiel Puig, who’s only really played three full seasons out of his seven MLB seasons. A quick look at his WAR shows only three seasons of more than 2 WAR, but when adjusting to WAR/162, five are over 2 WAR, and four are over 3 WAR.
However, extra caution should always be taken when looking at small sample sizes. Using a month’s worth of playing time to project a player’s full season WAR is ill-advised. Thus, you must be selective of when to use WAR/162, but it certainly does provide value if used in the right context.
Image from Beyond the Box Score (https://www.beyondtheboxscore.com/2010/11/16/1813082/how-common-is-a-one-win-above-replacement-player)