After reading Caple’s article, David Appelman and I began discussing the idea of reaching out to Sean Forman and seeing if he was interested in agreeing to a unified replacement level. Before we could actually even send that email, Sean reached out to us with the exact same idea. And so, today, we’re pleased to announce that Baseball-Reference and FanGraphs have adopted that unified replacement level, allowing our two models to now measure players on the same scale.
As David noted a few minutes ago, this new unified replacement level is now set at 1,000 WAR per 2,430 Major League games, which is the number of wins available in a 162 game season played by 30 teams. Or, an easier way to put it is that our new replacement level is now equal to a .294 winning percentage, which works out to 47.7 wins over a full season. Conveniently, this number is almost exactly halfway in between our previous replacement level (.265) and Baseball-Reference’s previous replacement level (.320), though the number wasn’t chosen solely as an equal compromise.
...The higher baseline brings our scale down slightly, but we think that change is worth making, as a unified replacement level will allow for comparisons of our apples versus their apples, and will eliminate needless confusion based around an area that didn’t need to cause confusion. These changes weren’t made lightly, and we know that there is always some resistance to any sort of change, but we hope that you see the unification of replacement level between the two sites as a positive overall.
While there will never be one single agreed upon WAR calculation — I’d call that a feature and not a bug, but that’s another post — the common baseline will give us a better opportunity to explore where the real differences are, rather than being tricked into seeing big gaps where none actually exist.
So, that’s the short version of the story behind this change. We’ll have more on this going forward, including a post coming later this afternoon on why we need replacement level to begin with, but for now, we hope you guys see this as a step forward for WAR as a metric.