How we rate our beers

This page explains how we measure beer quality and popularity so that highly rated beers with few check-ins can be compared fairly to widely distributed beers with tens of thousands of ratings. The system is inspired by baseball’s Wins Above Replacement (WAR). The metrics wOBAR (weighted Overall Beer Average Rating) and Beers Above Replacement (BAR) originated from Beergraphs.com; we use and extend that framework here.

Overview

  • Replacement level is the “floor” for each style: the worst-rated beer in the top 70% of that style by check-in volume. Beers are judged against this floor.
  • wOBAR (weighted Overall Beer Average Rating) is how much better a beer is than that floor: average rating minus replacement level.
  • Volume uses a logarithmic scale so that the first 10 check-ins matter as much as the next 90, and the first 100 as much as the next 9,900. This keeps low-volume beers meaningful.
  • BAR combines quality (wOBAR), volume, and a style-specific scale so that a “perfect” beer (5.0 rating, 1,000 check-ins) equals 15.0 BAR, matching the scale of peak single-season WAR.
  • Adjusted Volume adds a boost for low-check-in beers so they can compete on a more level playing field. ABR (Adjusted BAR) / TAP (Hall Rating) uses this adjusted volume instead of raw volume.

Core formulas

1. Replacement level (per style)

  • Restrict to beers in that style with valid ratings and at least a minimum number of check-ins (e.g. > 5).
  • Sort those beers by number of check-ins, descending.
  • Take the top 70% by count (e.g. count = floor(0.70 × listCount), minimum 1).
  • Replacement level = the lowest average rating among those top-70%-by-volume beers.

So replacement level is “the worst beer in the set of beers that get most of the check-ins in that style.”

2. wOBAR (weighted Overall Beer Average Rating)

How much better than the style floor a beer is:

wOBAR = Average Rating − Replacement Level

Example: If the replacement level for American IPA is 3.4 and a beer’s average rating is 4.1, then wOBAR = 4.1 − 3.4 = 0.7.

3. Volume (raw)

We use base-10 log of check-ins so that volume doesn’t dominate and small beers still matter:

Volume = log₁₀(# of check-ins)
  • 10 check-ins → 1
  • 100 → 2
  • 1,000 → 3
  • 10,000 → 4

4. Scale (per style)

We scale so that a “perfect” beer (5.0 rating, 1,000 check-ins) equals 15.0 BAR (analogous to Babe Ruth’s 1923 WAR). Scale depends on the style’s replacement level:

Scale = (15.0 / log₁₀(1,000)) / (5 − Replacement Level)

Since log₁₀(1,000) = 3:

Scale = 5 / (5 − Replacement Level)

If (5 − Replacement Level) ≤ 0, the scale is guarded (e.g. no division by zero).

5. BAR (Beers Above Replacement) — raw volume

BAR = wOBAR × Volume × Scale

This is the main “quality × popularity” metric before any adjustment for low check-ins.

6. Adjusted Volume and ABR / TAP (Hall Rating)

To give low-check-in beers a fairer shot, we add an Adjustment Factor (AF) to volume.

Adjustment Factor (AF):

AF = (C / log₁₀(check-ins + E)) + 1

Defaults: C = 5, E = 1.

Adjusted Volume = log₁₀(# of check-ins) + AF

Then the Hall Rating (TAP / ABR) is:

ABR = wOBAR × Adjusted Volume × Scale

So: same wOBAR and Scale as BAR, but Volume is replaced by Adjusted Volume.

Interpretation of AF:

  • The term log₁₀(check-ins) is the raw volume.
  • The term (C / log₁₀(check-ins + E)) + 1 is larger when check-ins are low, so low-volume beers get a volume boost.
  • As check-ins grow, AF shrinks toward 1, and Adjusted Volume behaves more like raw volume.

Example (C = 5, E = 1):

Beer Check-ins log₁₀(check-ins) AF (approx) Adjusted Volume (approx)
Beer A 10 1 5.81 6.81
Beer B 1,000 3 2.67 5.67

So a beer with 10 check-ins can have a higher adjusted volume than one with 1,000 check-ins, illustrating how the adjustment “levels the playing field” for underdogs.

BAR scale and descriptors

BAR (and similarly ABR/TAP) can be interpreted using the following ranges:

TAP range % of population (approx) Descriptor
10+10.26%Hall-of-Famer
8 to 101.01%MVP
6 to 80%All Star
4 to 60%Very Good
2 to 40%Above Average
0 to 286.13%Useful to Average
Below 02.6%Not Good

Glossary

ABV
Alcohol by volume.
ABR
Adjusted BAR; same as Hall Rating (TAP). Uses Adjusted Volume instead of raw Volume so low-check-in beers get a volume boost. ABR = wOBAR × Adjusted Volume × Scale.
BAR
Beers Above Replacement. A measure of a beer's quality (originated at Beergraphs.com): indexed to style (replacement level) and weighted by volume. BAR = wOBAR × Volume × Scale. See also the BAR scale table above.
BAR25
Sum of BAR for the top 25% of a brewery’s beers (by BAR or by some defined ordering). Measures the brewery’s “peak” output.
IBU
International Bittering Units; a measure of bitterness (with known limitations).
Replacement level
For a given style, the worst average rating among beers in the top 70% by check-in volume for that style. Represents the “lowest common denominator” widely available in that style.
Scale
Style-specific factor so that a perfect beer (5.0, 1,000 check-ins) equals 15.0 BAR. Scale = 5 / (5 − Replacement Level) (with guard when denominator ≤ 0).
Solid%
Percentage of a brewery’s beers that are above average (e.g. using Style+ or a chosen threshold). Example: Solid% = 50% means half of the brewery’s output is above average.
SOLID
Measure of how likely you are to get a great beer from a brewery. Based on distance from the mean and put on a 0–100 scale.
Style+
A beer’s rating compared to its style, with no volume weighting. Style+ = (Beer’s rating / Average style rating) × 100. Good for finding lesser-known beers that rate highly within their style.
TAP / Hall Rating
Same as ABR: wOBAR × Adjusted Volume × Scale. This is the metric used for Hall of Taps rankings.
Volume
Raw volume term: log₁₀(# of check-ins).
wOBAR
Weighted Overall Beer Average Rating (from Beergraphs.com): Average Rating − Replacement Level. Quality relative to the style floor.

Relative Beer Score (your rating vs style)

If you want to compare a personal rating to the style average:

Relative Beer Score = (Your Rating / Average Style Rating) × 100

Example: You rate an American IPA 4.2; average for the style is 3.8.
Relative Beer Score = (4.2 / 3.8) × 100 ≈ 110.5 (you rated it about 10.5% above the style average).

Implementation summary

  • Replacement level: Top 70% of style beers by check-in count; replacement level = min(rating) in that set.
  • wOBAR = Average Rating − Replacement Level.
  • Volume = log₁₀(check-ins).
  • Scale = 5 / (5 − Replacement Level), guarded.
  • BAR = wOBAR × Volume × Scale.
  • AF = (C / log₁₀(check-ins + E)) + 1, with C = 5, E = 1.
  • Adjusted Volume = log₁₀(check-ins) + AF.
  • ABR / TAP = wOBAR × Adjusted Volume × Scale.
  • Style+ = (Rating / Average style rating) × 100.

This formulation keeps the Hall of Taps math consistent across the site and any backend calculations.