\begin{tabular}{l cc c c c c}
\toprule
 & \multicolumn{2}{c}{Random split} & Forward split & Staleness & Level error & Re-levelled \\
\cmidrule{2-3}\cmidrule{4-4}
Model & All test sales & 2025--26 sales & 2025--26 sales & cost & $\hat{b}$ & MdAPE \\
\midrule
A1 Linear & 18.2 & 17.1 & 20.4 & +3.3 & +0.102 & 18.0 \\
A5 Quadratics & 19.2 & 18.5 & 23.3 & +4.8 & +0.171 & 18.3 \\
A6 Splines & 17.6 & 17.0 & 21.7 & +4.7 & +0.161 & 16.8 \\
B4 Month FE & 19.3 & 18.9 & 22.9 & +4.0 & +0.157 & 18.7 \\
C3 Grid 5.5 km & 18.7 & 18.3 & 24.3 & +6.0 & +0.182 & 18.8 \\
C4 Grid 1.1 km & 21.0 & 19.8 & 25.3 & +5.5 & +0.171 & 20.5 \\
D2 Ridge & 17.7 & 17.1 & 22.3 & +5.2 & +0.170 & 17.0 \\
D3 Random forest & 14.6 & 13.9 & 21.3 & +7.5 & +0.184 & 13.9 \\
D4 Boosting & 14.4 & 13.7 & 21.2 & +7.5 & +0.183 & 13.9 \\
D5 Boosting, no coord. & 23.2 & 21.0 & 26.2 & +5.2 & +0.188 & 21.3 \\
D6 $k$-NN comparables & 21.2 & 22.6 & 25.6 & +3.1 & +0.221 & 19.2 \\
\midrule
Test sales & 102,929 & 31,465 & 158,388 & & & \\
\bottomrule
\end{tabular}