\begin{table}[htbp]
\centering\small
\caption{Compared methods. All optimisation based methods are constraint subsets of the same model, solved by the same solver on the same arc set.}
\label{tab:methods}
\begin{tabular}{@{}>{\raggedright\arraybackslash}p{3.1cm}>{\raggedright\arraybackslash}p{2.2cm}>{\raggedright\arraybackslash}p{4.7cm}>{\raggedright\arraybackslash}p{4.3cm}@{}}
\toprule
Method & Type & What it does & Why it is included \\
\midrule
Top-1 candidate & heuristic & take the best candidate for each fragment & the naive use of a ranker \\
Mutual best & heuristic & accept $i\!\to\!j$ only if $j$ also prefers $i$ & standard practical heuristic \\
Bipartite matching & optimisation & uniqueness only & strongest method that does not model the slip \\
+ morphometry, context & optimisation & adds width gate and excavation unit & isolates the cheap gates \\
+ slip length & optimisation & adds order, acyclicity and length & isolates the chain structure \\
Pairwise constraints & optimisation & all constraints, pairwise proxies & our first formulation \\
Latent-slip (proposed) & optimisation & all constraints, latent $\Lambda,\Omega,\eta$ & the proposed model \\
Expert review (oracle) & reference & finds the partner if it is in top $k$ & upper bound on ranked-list workflows \\
\bottomrule
\end{tabular}
\end{table}