# Biblatex ambiguous citations aren't ambiguous - they have different years

I'm a bit annoyed with the typesetting of citations that biblatex deems "ambiguous". In the following example, I have two papers with the same first author, but a different second author in two different years. When citing in the main text, the second author is included before "et al", since biblatex deems these references to be ambiguous. However, the references were published in different years, so I cannot see why these are ambiguous. Is it possible to get these citations referenced using only the first author?

MWE

\documentclass{article}

\usepackage{filecontents}
\usepackage[hyperref,style=authoryear,natbib=true,maxbibnames=10,maxcitenames=2,useeditor=false,url=false,useprefix,giveninits=false]{biblatex}

\begin{filecontents}{jobname.bib}
@book{author_book,
title = {Book's title},
author = {Author, Some and Better, Some and Cetter, Some},
location = {The City},
publisher = {Publisher},
date = {2005},
}
@book{author_book2,
title = {Book's title},
author = {Author, Some and Getter, Some and Cetter, Some},
location = {The City},
publisher = {Publisher},
date = {2006},
}
\end{filecontents}

\bibliography{jobname}
% \bibliography{ref}

\begin{document}
Hello world \citet{author_book} \citet{author_book2}
\printbibliography
\end{document}



By default biblatex only considers the author (or more correctly the labelname) list to determine whether or not a citation is ambiguous. The year does not play a role. So even though the entries in the example are not ambiguous if you take the year into account, biblatex will still disambiguate them, because the name lists alone are ambiguous.

With

uniquename=minyear,


biblatex will only disambiguate name lists if they would be ambiguous within the same year.

With

uniquename=false,


name lists are never disambiguated.

See also p. 64 (documentation of the uniquelist option) and §4.11.4 Name Disambiguation, esp. §4.11.4.2 Lists of Names (uniquelist), pp. 294-295, of the biblatex documentation.

\documentclass{article}

\usepackage[style=authoryear, maxbibnames=10, maxcitenames=2, uniquelist=minyear]{biblatex}

\usepackage{filecontents}
\begin{filecontents}{\jobname.bib}
@book{author_book,
title     = {Book's title},
author    = {Author, Some and Better, Some and Cetter, Some},
location  = {The City},
publisher = {Publisher},
date      = {2005},
}
@book{author_book2,
title     = {Book's title},
author    = {Author, Some and Getter, Some and Cetter, Some},
location  = {The City},
publisher = {Publisher},
date      = {2006},
}
@book{uthor_book,
title     = {Book's title},
author    = {Uthor, Anne and Better, Some and Cetter, Some},
location  = {The City},
publisher = {Publisher},
date      = {2018},
}
@book{uthor_book2,
title     = {Book's title},
author    = {Uthor, Anne and Getter, Some and Cetter, Some},
location  = {The City},
publisher = {Publisher},
date      = {2018},
}
\end{filecontents}