These changes reflect a complete review of books on graph theory and combinatorics in addition to the normal changes.

Added:

***Benjamin and Quinn, Proofs that Really Count
***Bressoud, Proofs and Confirmations: The Story of the Alternating Sign Matrix Conjecture
***Wilson, Four Colours Suffice
**Aigner, A Course in Enumeration
**Bóna, Introduction to Enumerative Combinatorics
**Harary, Graph Theory
**Pólya, Tarjan, and Wood, Notes on Introductory Combinatorics
**Roberts and Tesman, Applied Combinatorics
**Rotman, Advanced Modern Algebra
**Ziegler, Lectures on Polytopes
*Alsina and Nelsen, Charming Proofs: A Journey into Elegant Mathematics
*Andreescu and Feng, A Path to Combinatorics for Undergraduates
*Andrews and Eriksson, Integer Partitions
*Berndt, Number Theory in the Spirit of Ramanujan
*Bóna, A Walk through Combinatorics: An Introduction to Enumeration and Graph Theory
*Bóna, Combinatorics of Permutations
*Börgers, Mathematics of Social Choice: Voting, Compensation, and Division
*Chartrand and Zhang, Introduction to Graph Theory
*Cheney and Kincaid, Numerical Mathematics and Computing
*Graver, Counting on Frameworks: Mathematics to Aid the Design of Rigid Structures
*Landman and Robertson, Ramsey Theory on the Integers
*Lando, Lectures on Generating Functions
*Lovász and Plummer, Matching Theory
*Marcus, Combinatorics: A Problem Oriented Approach
*Rosen, Discrete Mathematics and its Applications
*Schlick, Molecular Modeling and Simulation: An Interdisciplinary Guide
*Stillwell, Roads to Infinity
*Tutte, Graph Theory As I Have Known It
*Van Lint and Wilson, A Course in Combinatorics
Aigner and Behrens, eds., Mathematics Everywhere
Alkinson and Han, Theoretical Numerical Analysis: A Functional Analysis Framework
Awodey, Category Theory
Banchoff and Lovett, Differential Geometry of Curves and Surfaces
Bär,  Elementary Differential Geometry
Bezdek, Classical Topics in Discrete Geometry
Björner and Brenti, Combinatorics of Coxeter Groups
Bollobás, Extremal Graph Theory
Bollobás, Modern Graph Theory
Börner, Atlas of Science: Visualizing What We Know
Colbourn and Dinitz, eds., Handbook of Combinatorial Design
Complex Systems Modelling Group, Modelling in Healthcare
Cvetkovic, Rowlinson, and Simi, An Introduction to the Theory of Graph Spectra
Diestel, Graph Theory
Duistermaat, Distributions: Theory and Applications
Durbin, Modern Algebra
Durrett, Random Graph Dynamics
Easley and Kleingberg, Networks, Crowds, and Markets: Reasoning about  a Highly Connected World
Ethier, The Doctrine of Chances: Probabilistic Aspects of Gambling
Gallian, ed., Mathematics and Sports
Gloumbic and Flartman, eds., Graph Theory, Combinatorics, and Algorithms: Interdisciplinary Applications
Harman, The Price of Altruism: George Price and the Search for the Origins of Kindness
Helms, Introduction to Probability Theory with Contemporary Applications
Holme, Geometry: Our Cultural Heritage
Huber and Ronchetti, Robust Statistics
Ionin and Shrikhande, Combinatorics of Symmetric Designs
Karp and Vogeli, eds. Russian Mathematics Education
Lovász, Combinatorial Problems and Exercises
Lovett, Differential Geometry of Manifolds
Lux and Pahlings, Representations of Groups: A Computational Approach
Mumford, Selected Papers I, II
Nathanson, Additive Number Theory: The Classical Bases
Newman, Networks: An Introduction
Purrington, The First Professional Scientist: Robert Hooke and the Royal Society of London
Radin, Miles of Tiles
Rosser, Logic for Mathematicians
Shimura, Introduction to the Arithmetic Theory of Automorphic Functions
Sigmund, The Calculus of Selfishness
Tao and Vu, Additive Combinatorics
Verzani, Using R for Elementary Statistics
Yau, The Shape of Inner Space

Removed:
Roberts, Applied Combinatorics

Ratings Changed:

Upgrades
Aigner, Combinatorial Theory, from BLL to BLL*
Batten, Combinatorics of Finite Geometries, from BLL to BLL*
Biggs, Algebraic Graph Theory, from BLL to BLL*
Biggs, Discrete Mathematics, from BLL* to BLL**
Bogart, Introductory Combinatorics, from BLL to BLL**
Brualdi and Ryser, Combinatorial Matrix Theory, from BLL to BLL*
König, Theory of Finite and Infinite Graphs, from BLL to BLL*
Rota, Studies in Combinatorics, from BLL to BLL*
Stanley, Enumerative Combinatorics I and II, from BLL** to BLL***
Stanton and White, Constructive Combinatorics, from BLL to BLL*
Tucker, Applied Combinatorics, from BLL to BLL**

Downgrades
Alexanderson, Kloskinski, and Larson, The William Lowell Putnam Mathematical Competition: Problems and Solutions, 1965–1984, from BLL** to BLL*
Anderson, A First Course in Combinatorial Mathematics, from BLL* to BLL
Anton, Elementary Linear Algebra, from BLL* to BLL (all versions)
Beckenbach and Bellman, An Introduction to Inequalities, from BLL** to BLL
Berge, Graphs, from BLL* to BLL
Birkhoff and Mac Lane, A Survey of Modern Algebra, from BLL*** to BLL**
Bondy and Murty, Graph Theory, from BLL*** to BLL**
Cockcroft, Mathematics Counts, from BLL* to BLL
Cohen, Basic Techniques of Combinatorial Theory, from BLL* to BLL
Davis and Rabinowitz, Methods of Numerical Integration, from BLL** to BLL
Dudeney, Amusements in Mathematics, from BLL*** to BLL
Epp, Discrete Mathematics and Its Applications, from BLL* to BLL
Erdös and Spencer, Probabilistic Methods in Combinatorics, from BLL* to BLL
Gardner, Riddles of the Sphynx and other Mathematical Puzzle Tales, from BLL* to BLL
Honsberger, Mathematical Gems I, Mathematical Gems II, from BLL** to BLL*
Honsberger, More Mathematical Morsels, from BLL* to BLL
Honsberger, ed. Mathematical Plums, from BLL* to BLL
Johnsonbaugh, Discrete Mathematics, from BLL* to BLL
Kraitchik, Mathematical Recreations, from BLL*** to BLL
Luce, Games and Decisions, from BLL*** to BLL**
Mosteller, Fifty Challenging Problems in Probability with Solutions, from BLL** to BLL
NIST Handbook of Mathematical Functions, from BLL* to BLL
Niven, The Mathematics of Choice, from BLL*** to BLL*
Penfold Street and Street, Combinatorics of Experimental Designs, from BLL* to BLL
Ross and Wright, Discrete Mathematics, from BLL** to BLL*
Saaty, The Four-Color Problem: Assaults and Conquest, from BLL* to BLL
Sloane,  A Handbook of Integer Sequences, from BLL* to BLL
Smith, A Source Book in Mathematics, from  BLL** to BLL*
Struik, A Concise History of Mathematics, from BLL*** to BLL**
Welsh, Matroid Theory, from BLL* to BLL
Wilson and Watkins, Graphs: An Introductory Approach, from BLL** to BLL*