Continuing on with our series explaining win values, today, we get back to positional adjustments. We spent a lot of time talking about them the last few weeks, so if you haven’t read those articles, I’d suggest catching up first. A basic summary of the need for position adjustments follows below, for those who want a short version.
Since we started off with wRAA (which is offensive runs above or below league average) and UZR (which is defensive runs above or below league average at a specific position), we need to calibrate the scale to make up for the fact that some positions are significantly harder to play than others. It is much harder to find a +5 SS than it is to find a +5 2B, and we need to represent that in the Win Value system. That’s what the position adjustments are there for.
Traditionally, offensive position adjustments have been popular, which aligns the positions by adjusting on the basis of the difference in offensive runs. However, due to the variability in offensive performance from year to year, that can lead to miscalculations, such as believing that an NL 2B and an NL SS were equal in 2008 because they had the same batting line. Clearly, shortstops are better defenders than second baseman, and we have to reflect this in their value.
That’s why we prefer a defensive position adjustment. The position adjustment scale we use is as follows:
Catcher: +12.5 runs (all are per 162 defensive games)
First Base: -12.5 runs
Second Base: +2.5 runs
Third Base: +2.5 runs
Shortstop: +7.5 runs
Left Field: -7.5 runs
Center Field: +2.5 runs
Right Field: -7.5 runs
Designated Hitter: -17.5 runs
To read more about how these were arrived at, check out these threads at The Book blog.
The position adjustments are then scaled to match the games played at each position for a particular player. This way, players that spend time at multiple positions get a hybrid adjustment based on their playing time at the respective spots.
Once you add the wRAA, UZR, and position adjustment together, you have the sum of a player’s value above or below league average. If we used Chase Utley as an example, he gets 37.1 wRAA, 19.2 UZR, and 2.3 Position Adjustment for a total of +58.6 runs. In 2008, Chase Utley was 58.6 runs better than a league average player. If you want to start handing out credit for the World Series title in Philly, give him the most, because that’s outstanding.
However, now we have value above or below average, but what is average worth? Clearly, it’s worth more than zero, as teams pay significant cash for league average players every winter, and a team full of league average players would win 81 games and generate positive revenue for their franchise. But, in terms of dollar values, we don’t have a fixed baseline for what a league average player is paid.
However, you know what we do have a fixed baseline for? The league minimum player. MLB has set $400,000 as the least any player can get paid, so we know that a player who is completely replaceable is worth $400,000. That makes replacement level a good target to calculate value off of. So, this afternoon, we’ll talk about replacement level and how that is defined.
Dave is the Managing Editor of FanGraphs.