Changes in version 1.1-3                        

  - fix cross-references in documentation
  - update references to JSS articles
  - convert Sweave vignette to bookdown for greater accessibility

                 Changes in version 1.1-2 (2020-02-03)                  

  - use absolute vs relative link in README so it works on CRAN

                        Changes in version 1.1-1                        

  - improve the way BTm finds variables passed to outcome, player1 etc,
    so that it works when run in a separate environment.
  - convert old tests to unit tests.

                 Changes in version 1.1-0 (2019-05-11)                  

  - anova.BTm now respects test and dispersion arguments for models that
    inherit from glm.
  - fix bug in anova.BTmlist affecting models where ability is modelled
    by predictors but ability is estimated separately for some players
    due to missing values.
  - fix bug in glmmPQL affecting models with . in formula and either
    offset or weights specified.
  - standardize tests to use random number generation as in R 2.10 for
    backwards compatibility.

                 Changes in version 1.0-9 (2019-02-25)                  

  - fix bug in setting contrasts in internal function Diff() that gave
    warning under R-devel.
  - update urls (using https where possible).
  - fix a couple of if statements where argument could be > 1.

                 Changes in version 1.0-8 (2017-09-20)                  

  - fix bug in qvcalc.BTabilities

                 Changes in version 1.0-7 (2017-08-26)                  

Improvements

  - new examples of prediction added, including using predict.BTm to
    estimate abilities with non-player abilities set to non-zero values
    (for models with a fixed reference category).
  - qvcalc.BTabilities moved over from package qvcalc.
  - package imports rather than depends on lme4.

Changes in behaviour

  - default level in predict.BTm and predict.glmmPQL is 0 if a fixed
    effects model has been fitted, 1 otherwise.

Bug fixes

  - BTabilities now works (again) for models where the reference
    category is not the first player. Players are kept in their original
    order (levels of player1 and player2), but the abilities are
    returned with the appropriate reference.

  - BTabilities now works when ability is modelled by covariates and
    some parameters are inestimable (e.g. as in chameleons.model on
    ?chameleons).

  - predict.BTglmmPQL now works for models with inestimable parameters

                 Changes in version 1.0-6 (2015-02-09)                  

Changes in behaviour

  - BTabilities now returns NA for unidentified abilities

Bug fixes

  - BTabilities now respects contrasts argument and contrasts attributes
    of player1 and player2 factors. Also handle unidentified
    coefficients correctly.

                 Changes in version 1.0-5 (2014-06-17)                  

Bug fixes

  - no longer imports from gnm, so gnm need not be installed.

                 Changes in version 1.0-4 (2013-09-21)                  

Bug fixes

  - depends on lme4 (>=1.0).

                        Changes in version 1.0-3                        

New Features

  - updated football data to include full 2011-12 season.

                 Changes in version 1.0-2 (2013-07-18)                  

New Features

  - added football example presented at useR! 2013 with generalised
    Davidson model for ties.

                 Changes in version 1.0-1 (2013-06-20)                  

Bug fixes

  - renamed glmmPQL object BTglmmPQL to avoid conflict with lme4 (which
    loads MASS).
  - fixed BTm so that it is able to find variables when called inside
    another function (stackoverflow.com question 14911525).

                 Changes in version 1.0-0 (2012-05-14)                  

  - updated references and CITATION to cite JSS paper on BradleyTerry2

                        Changes in version 0.9-7                        

Bug fixes

  - fixed anova.BTmlist to work for models with random effects

  - allow models to be specified with no fixed effects

Improvements

  - updated vignette, including example of bias-reduction, a new example
    incorporating random effects and a new example on preparing data for
    use with package

                 Changes in version 0.9-6 (2011-09-19)                  

Bug fixes

  - fixed offset argument to work as documented

  - corrected documentation for citations data

Improvements

  - updated vignette, to provide more explanation of setting up the data

                 Changes in version 0.9-5 (2011-02-25)                  

  - updated contact details

                 Changes in version 0.9-4 (2010-10-12)                  

New Features

  - added ice hockey example presented at useR! 2010

Bug fixes

  - predict.BTm now works for models with no random effects and handles
    new individuals with missing values in predictors.

                 Changes in version 0.9-3 (2010-10-04)                  

New Features

  - added predict method for BTm objects.

Bug fixes

  - fixed bug in BTm.setup causing problems in finding variables when
    BTm nested within another function.