What is WAR?
Wins Above Replacement summarizes a player's total contribution as the number of extra wins he provides over a replacement-level call-up. FanGraphs and Baseball-Reference compute it differently, but both blend offense, defense, baserunning and park context.
How this estimate works
A full WAR needs defense and baserunning data no browser tool can know, so this calculator builds the offensive core only: runs above average from wRC+ and plate appearances, plus the positional and replacement-level adjustments (~20 runs per 600 PA). It is explicitly an estimate — ideal for sanity checks, not record books.
Common use cases
- Gut-checking a talking head's WAR claim
- Fantasy valuation where offense dominates
- Learning how the WAR sausage is made
Formula & honesty
WAR ≈ (RAA + positional + replacement) ÷ 10, with RAA = PA × (lgR/PA) × (wRC+ − 100) ÷ 100. Add defense and baserunning for the real thing.
Frequently Asked Questions
Why can't this be exact?
Official WAR needs UZR/DRS defense, baserunning runs and park factors — outside a browser's reach.
What is a good WAR?
2+ is a solid starter, 4–5 is All-Star, 6+ is MVP conversation.
Is wRC+ required?
It is the cleanest offensive input; raw wOBA or runs can be converted offline.
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