Tag Archives: wins above replacement

Rugby league’s replacement player

Last week we looked at valuing players, specifically Tom Trbojevic, Daly Cherry-Evans and Addin Fonua-Blake, by their contributions to Manly’s winning ways. There were two problems though:

  1. How do we deal with someone like Marty Taupau? He’s played all of the games this year so we can’t find an understudy to compare him to.
  2. What if your understudy is pretty good? Cherry-Evans looks like he is comparatively less valuable than his colleagues because Kane Elgey is about 20% more productive at halfback than Brendan Elliot or Toafofoa Sipley were at their respective positions.

We should establish a fixed benchmark to compare players against.

Baseball uses the concept of a “replacement level“. I touched on it briefly last week but the rugby league equivalent would be a top level reserve grader who can be acquired for the league’s minimum salary ($105,000 in 2019). By definition, the replacement level player provides the right value for money for that salary. If a player provides less value, they shouldn’t be in first grade because they can’t justify their pay packet. The trick is to find players who provide more value and then pay them accordingly to win games for your club.

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Primer – PPG and WARG

Turns out that StatScore didn’t pan out the way I had hoped. There were some conceptual errors but the biggest was that I wanted a measure of rate and a measure of volume and you can’t have one statistic that does both. It’s like having one number that meaningfully states that a boxer is both the best in the world pound-for-pound but also the best boxer in the world who can beat anyone irrespective of weight classes. The world doesn’t work like that. As a result, there was some okay, but not great, player analysis. Unfortunately, the creation of a new tool requires that you use it for a while on new scenarios in order to evaluate it’s usefulness. Sometimes it doesn’t pan out as well as you would have hoped.

Also, the name sucked.

So I went back to the drawing board. There were some salvageable concepts from StatScore that have been repackaged, with corrections made for some fundamental mistakes, and repurposed into new player rating systems: PPG and WARG.

moneyball

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