Fraction of observed targets as a function of target density for low- (upper panel) and high-resolution (lower panel) targets. The targeting simulation has been run using one, two, or three tiles overlaid (with small random shifts). Each target was observed only once and all fibres were used for science targets. Green solid lines show theoretical expectations for perfect fibre to target allocation. Vertical dashed lines show fibre density on the sky for low- (upper panel) and high-resolution (lower panel) spectrograph fibres.