Embodiments of the present invention include a medical probe having a flexible insertion tube, a basket assembly, and a plurality of electrodes. The basket assembly has a proximal end that is connected distally to the insertion tube and includes a plurality of resilient spines, which have respective outer sides and inner sides and are configured to bow radially outward from an axis of the basket assembly and are conjoined at the proximal end and at a distal end of the basket assembly. The plurality of electrodes are fixed to respective ones of the spines in respective longitudinal positions that are staggered on any given spine relative to the longitudinal positions of the electrodes on the spines adjacent to the given spine, and which include a conductive material that is biased towards the respective outer sides of the spines.